Method for transmitting and receiving shared channel in wireless communication system, and device supporting same

ABSTRACT

In a method for transmitting and receiving a shared channel in a wireless communication system, the method performed by a terminal is characterized by comprising: a step for receiving, from a base station, first resource information for transmitting and receiving a shared channel; and a step for receiving, from the base station, the shared channel on a first resource determined on the basis of the first resource information or transmitting, to the base station, the shared channel on the first resource.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/514,157 filed on Oct. 29, 2021, which a continuation of PCTInternational Application No. PCT/KR2020/005924, which was filed on May4, 2020, and which claims priority under 35 U.S.C 119(a) to KoreanPatent Application No. 10-2019-0051862 filed with the KoreanIntellectual Property Office on May 2, 2019, Korean Patent ApplicationNo. 10-2019-0054577 filed with the Korean Intellectual Property Officeon May 9, 2019, and Korean Patent Application No. 10-2019-0141791 filedwith the Korean Intellectual Property Office on Nov. 7, 2019. Thedisclosures of the above patent applications are incorporated herein byreference in their entirety.

TECHNICAL FIELD

The present specification relates to a wireless communication systemand, more particularly, to a method and a device for transmitting orreceiving a shared channel.

BACKGROUND ART

After commercialization of 4th generation (4G) communication system, inorder to meet the increasing demand for wireless data traffic, effortsare being made to develop new 5th generation (5G) communication systems.The 5G communication system is called as a beyond 4G networkcommunication system, a post LTE system, or a new radio (NR) system. Inorder to achieve a high data transfer rate, 5G communication systemsinclude systems operated using the millimeter wave (mmWave) band of 6GHz or more, and include a communication system operated using afrequency band of 6 GHz or less in terms of ensuring coverage so thatimplementations in base stations and terminals are under consideration.

A 3rd generation partnership project (3GPP) NR system enhances spectralefficiency of a network and enables a communication provider to providemore data and voice services over a given bandwidth. Accordingly, the3GPP NR system is designed to meet the demands for high-speed data andmedia transmission in addition to supports for large volumes of voice.The advantages of the NR system are to have a higher throughput and alower latency in an identical platform, support for frequency divisionduplex (FDD) and time division duplex (TDD), and a low operation costwith an enhanced end-user environment and a simple architecture.

For more efficient data processing, dynamic TDD of the NR system may usea method for varying the number of orthogonal frequency divisionmultiplexing (OFDM) symbols that may be used in an uplink and downlinkaccording to data traffic directions of cell users. For example, whenthe downlink traffic of the cell is larger than the uplink traffic, thebase station may allocate a plurality of downlink OFDM symbols to a slot(or subframe). Information about the slot configuration should betransmitted to the terminals.

In order to alleviate the path loss of radio waves and increase thetransmission distance of radio waves in the mmWave band, in 5Gcommunication systems, beamforming, massive multiple input/output(massive MIMO), full dimensional MIMO (FD-MIMO), array antenna, analogbeam-forming, hybrid beamforming that combines analog beamforming anddigital beamforming, and large scale antenna technologies are discussed.In addition, for network improvement of the system, in the 5Gcommunication system, technology developments related to evolved smallcells, advanced small cells, cloud radio access network (cloud RAN),ultra-dense network, device to device communication (D2D), vehicle toeverything communication (V2X), wireless backhaul, non-terrestrialnetwork communication (NTN), moving network, cooperative communication,coordinated multi-points (CoMP), interference cancellation, and the likeare being made. In addition, in the 5G system, hybrid FSK and QAMmodulation (FQAM) and sliding window superposition coding (SWSC), whichare advanced coding modulation (ACM) schemes, and filter bankmulti-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparsecode multiple access (SCMA), which are advanced connectivitytechnologies, are being developed.

Meanwhile, in a human-centric connection network where humans generateand consume information, the Internet has evolved into the Internet ofThings (IoT) network, which exchanges information among distributedcomponents such as objects. Internet of Everything (IoE) technology,which combines IoT technology with big data processing technologythrough connection with cloud servers, is also emerging. In order toimplement IoT, technology elements such as sensing technology,wired/wireless communication and network infrastructure, serviceinterface technology, and security technology are required, so that inrecent years, technologies such as sensor network, machine to machine(M2M), and machine type communication (MTC) have been studied forconnection between objects. In the IoT environment, an intelligentinternet technology (IT) service that collects and analyzes datagenerated from connected objects to create new value in human life canbe provided. Through the fusion and mixture of existing informationtechnology (IT) and various industries, IoT can be applied to fieldssuch as smart home, smart building, smart city, smart car or connectedcar, smart grid, healthcare, smart home appliance, and advanced medicalservice.

Accordingly, various attempts have been made to apply the 5Gcommunication system to the IoT network. For example, technologies suchas a sensor network, a machine to machine (M2M), and a machine typecommunication (MTC) are implemented by techniques such as beamforming,MIMO, and array antennas. The application of the cloud RAN as the bigdata processing technology described above is an example of the fusionof 5G technology and IoT technology. Generally, a mobile communicationsystem has been developed to provide voice service while ensuring theuser's activity.

However, the mobile communication system is gradually expanding not onlythe voice but also the data service, and now it has developed to theextent of providing high-speed data service. However, in a mobilecommunication system in which services are currently being provided, amore advanced mobile communication system is required due to a shortagephenomenon of resources and a high-speed service demand of users.

DISCLOSURE OF INVENTION Technical Problem

The present specification is to provide a method for transmitting orreceiving an uplink shared channel.

Solution to Problem

The present specification provides a method for transmitting orreceiving a shared channel in a wireless communication system.

Specifically, a method performed by a terminal includes: receiving, froma base station, first resource information for transmission or receptionof a shared channel, wherein the first resource information includes asymbol length and a relative start symbol index in a time domainresource for transmission or reception of the shared channel; andreceiving, from the base station, the shared channel on a first resourcedetermined based on the first resource information, or transmitting theshared channel to the base station on the first resource, wherein astart symbol index of the first resource is determined based on therelative start symbol index and a pre-defined reference symbol index.

In the present specification, the reference symbol index is 0.

In the present specification, the reference symbol index is determinedbased on a length and a start symbol of a resource including the firstresource information.

In the present specification, the first resource is determined based ona first subcarrier spacing (SCS) of a first cell including the firstresource information and a second SCS of a second cell including theshared channel.

In the present specification, if the first SCS and the second SCS arethe same, the reference symbol index is an index of an earliest symbolamong symbols including the first resource information of the firstcell.

In the present specification, if the first SCS is smaller than thesecond SCS, the reference symbol index is an index of an earliest symbolamong symbols including the shared channel of the second cell, whichoverlap in the time domain with symbols including the first resourceinformation of the first cell.

In the present specification, if the first SCS is smaller than thesecond SCS, the reference symbol index is an index of a last symbolamong symbols including the shared channel of the second cell, whichoverlap in the time domain with symbols including the first resourceinformation of the first cell.

In the present specification, if the first SCS is greater than thesecond SCS, the reference symbol index is an index of an earliest symbolamong symbols that do not precede symbols including the first resourceinformation, from among symbols including the shared channel of thesecond cell, which overlap in the time domain with symbols of the firstcell.

In the present specification, the first resource information furtherincludes a first position of a demodulation-reference signal (DM-RS)mapped to the first resource.

In the present specification, if the first resource includes the firstposition, the DM-RS is mapped to the first position, and if the firstresource does not include the first position, the DM-RS is mapped to asymbol indicated by the start symbol index of the first resource.

In the present specification, if the shared channel is transmitted firston the first resource and is repeatedly transmitted second on a secondresource, the DM-RS is mapped to the first position in the firstresource, and the DM-RS is mapped to a first symbol of the secondresource in the second resource.

In the present specification, if the shared channel is transmitted firston the first resource and is repeatedly transmitted second on a secondresource, the DM-RS is mapped to the first position in the firstresource, the DM-RS is mapped to a position corresponding to the firstposition in the second resource, and the corresponding position is aposition separated from a first symbol of a second duration by aduration that the first position and a first symbol of the firstresource are separated.

In the present specification, the DM-RS is mapped to a symbol indicatedby the start symbol index of the first resource regardless of the firstposition.

In the present specification, the method further includes receiving,from the base station, second resource information for transmission orreception of the shared channel, wherein the second resource informationincludes information on a use of multiple symbols constituting a slot ofthe first resource, and the reference symbol index is determined basedon the first resource information and the second resource information.

In the present specification, if the shared channel is transmitted tothe base station on the first resource, the reference symbol index is anindex of a symbol, which has a direction configured to flexible and isimmediately subsequent to a last symbol the use of which is configuredto downlink, from among the multiple symbols.

In the present specification, if the shared channel is transmitted tothe base station on the first resource, the reference symbol index is anindex of a symbol, which has a use configured to flexible or uplink andis immediately subsequent to a gap symbol located after a last symbolthe use of which is configured to downlink, from among the multiplesymbols.

In the present specification, a terminal for transmitting or receiving ashared channel in a wireless communication system includes: atransceiver; a processor; and

a memory connected to the processor and configured to store instructionsfor operations executed by the processor, wherein the operationsinclude: receiving first resource information for transmission of ashared channel from a base station, wherein the first resourceinformation includes a symbol length and a relative start symbol indexin a time domain resource for transmission of the shared channel; andreceiving, from the base station, the shared channel on a first resourcedetermined based on the first resource information, or transmitting theshared channel to the base station on the first resource, wherein astart symbol index of the first resource is determined based on therelative start symbol index and a pre-defined reference symbol index.

In the present specification, the reference symbol index is 0.

In the present specification, the reference symbol index is determinedbased on a resource including the first resource information.

In the present specification, the first resource is determined based ona first subcarrier spacing (SCS) of a first cell including the firstresource information and a second SCS of a second subcarrier of a secondcell including the shared channel.

Advantageous Effects of Invention

The present specification provides a method for efficiently determininga resource used for shared channel transmission.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates an example of a wireless frame structure used in awireless communication system.

FIG. 2 illustrates an example of a downlink (DL)/uplink (UL) slotstructure in a wireless communication system.

FIG. 3 is a diagram for explaining a physical channel used in a 3GPPsystem and a typical signal transmission method using the physicalchannel.

FIGS. 4 a and 4 b illustrate an SS/PBCH block for initial cell access ina 3GPP NR system.

FIGS. 5 a and 5 b illustrate a procedure for transmitting controlinformation and a control channel in a 3GPP NR system.

FIG. 6 illustrates a control resource set (CORESET) in which a physicaldownlink control channel (PUCCH) may be transmitted in a 3GPP NR system.

FIG. 7 illustrates a method for configuring a PDCCH search space in a3GPP NR system.

FIG. 8 is a conceptual diagram illustrating carrier aggregation.

FIG. 9 is a diagram for explaining signal carrier communication andmultiple carrier communication.

FIG. 10 is a diagram showing an example in which a cross carrierscheduling technique is applied.

FIG. 11 is a block diagram showing the configurations of a UE and a basestation according to an embodiment of the present disclosure.

FIG. 12 is a diagram illustrating a slot configuration of a TDD-basedmobile communication system according to an embodiment of the presentdisclosure.

FIG. 13 is a diagram illustrating a physical uplink control channel(PUCCH) used in a wireless communication system according to anembodiment of the present disclosure.

FIG. 14 is a diagram illustrating a method of transmitting PUCCH in aslot.

FIGS. 15 a and 15 b are diagrams illustrating an example of transmittingPUCCH to another slot according to a change in a slot configuration.

FIG. 16 is a diagram illustrating a slot in which repetition PUCCHtransmission is performed according to a slot configuration.

FIG. 17 illustrates whether PUCCH is transmitted according to a slotconfiguration.

FIG. 18 illustrates repetition mini-slot-level PUSCH transmissionaccording to an embodiment of the present disclosure.

FIG. 19 illustrates repetition mini-slot-level PUSCH transmissionaccording to another embodiment of the present disclosure.

FIG. 20 is a diagram illustrating a condition in which repetitionmini-slot-level PUSCH transmission ends according to an embodiment ofthe present disclosure.

FIG. 21 is a diagram illustrating a counting rule of repetitionmini-slot-level PUSCH transmission according to an embodiment of thepresent disclosure.

FIG. 22 is a diagram illustrating PUSCH transmission in consideration ofa slot boundary according to an embodiment of the present disclosure.

FIG. 23 to FIG. 26 are diagrams illustrating repetition PUSCHtransmission in consideration of multi-segment transmission andrepetition mini-slot-level PUSCH transmission according to an embodimentof the present disclosure.

FIG. 27 is a diagram illustrating repetition PUSCH transmissionaccording to an embodiment of the present disclosure.

FIG. 28 is a diagram for a method of locating a DM-RS in repetitionPUSCH transmission according to an embodiment of the present disclosure.

FIG. 29 is a diagram illustrating a method of determining a referencesymbol index of PDSCH according to an embodiment of the presentdisclosure.

FIG. 30 is a flowchart illustrating an operation procedure in a terminalperforming a method of transmitting a shared channel according to anembodiment of the present disclosure.

BEST MODE FOR CARRYING OUT THE INVENTION

Terms used in the specification adopt general terms which are currentlywidely used as possible by considering functions in the presentdisclosure, but the terms may be changed depending on an intention ofthose skilled in the art, customs, and emergence of new technology.Further, in a specific case, there is a term arbitrarily selected by anapplicant and in this case, a meaning thereof will be described in acorresponding description part of the present disclosure. Accordingly,it intends to be revealed that a term used in the specification shouldbe analyzed based on not just a name of the term but a substantialmeaning of the term and contents throughout the specification.

Throughout this specification and the claims that follow, when it isdescribed that an element is “connected” to another element, the elementmay be “directly connected” to the other element or “electricallyconnected” to the other element through a third element. Further, unlessexplicitly described to the contrary, the word “comprise” will beunderstood to imply the inclusion of stated elements but not theexclusion of any other elements unless otherwise stated. Moreover,limitations such as “more than or equal to” or “less than or equal to”based on a specific threshold may be appropriately substituted with“more than” or “less than”, respectively, in some exemplary embodiments.

The following technology may be used in various wireless access systems,such as code division multiple access (CDMA), frequency divisionmultiple access (FDMA), time division multiple access (TDMA), orthogonalfrequency division multiple access (OFDMA), single carrier-FDMA(SC-FDMA), and the like. The CDMA may be implemented by a wirelesstechnology such as universal terrestrial radio access (UTRA) orCDMA2000. The TDMA may be implemented by a wireless technology such asglobal system for mobile communications (GSM)/general packet radioservice (GPRS)/enhanced data rates for GSM evolution (EDGE). The OFDMAmay be implemented by a wireless technology such as IEEE 802.11(Wi-Fi),IEEE 802.16(WiMAX), IEEE 802-20, evolved UTRA (E-UTRA), and the like.The UTRA is a part of a universal mobile telecommunication system(UMTS). 3rd generation partnership project (3GPP) long term evolution(LTE) is a part of an evolved UMTS (E-UMTS) using evolved-UMTSterrestrial radio access (E-UTRA) and LTE-advanced (A) is an evolvedversion of the 3GPP LTE. 3GPP new radio (NR) is a system designedseparately from LTE/LTE-A, and is a system for supporting enhancedmobile broadband (eMBB), ultra-reliable and low latency communication(URLLC), and massive machine type communication (mMTC) services, whichare requirements of IMT-2020. For the clear description, 3GPP NR ismainly described, but the technical idea of the present disclosure isnot limited thereto.

Unless otherwise specified in this specification, a base station mayrefer to a next generation node B (gNB) as defined in 3GPP NR.Furthermore, unless otherwise specified, a terminal may refer to a userequipment (UE). Hereinafter, in order to facilitate understanding of thedescription, each content is separately divided into embodiments anddescribed, but each of the embodiments may be used in combination witheach other. In the present disclosure, the configuration of the UE mayindicate configuration by the base station. Specifically, the basestation may transmit a channel or signal to the UE to configure anoperation of the UE or a parameter value used in a wirelesscommunication system.

FIG. 1 illustrates an example of a wireless frame structure used in awireless communication system.

Referring to FIG. 1 , the wireless frame (or radio frame) used in the3GPP NR system may have a length of 10 ms (Δf_(max)N_(f)/100)*T_(c)). Inaddition, the wireless frame includes 10 subframes (SFs) having equalsizes. Herein, Δf_(max)480*10³ Hz, N_(f)=4096,T_(c)=1/(Δf_(ref)*N_(f,ref)), Δf_(ref)=15*10³ Hz, and N_(f,ref)=2048.Numbers from 0 to 9 may be respectively allocated to 10 subframes withinone subframe. Each subframe has a length of 1 ms and may include one ormore slots according to a subcarrier spacing. More specifically, in the3GPP NR system, the subcarrier spacing that may be used is 15*2^(μ) kHz,and μ can have a value of μ=0, 1, 2, 3, 4 as subcarrier spacingconfiguration. That is, 15 kHz, 30 kHz, 60 kHz, 120 kHz and 240 kHz maybe used for subcarrier spacing. One subframe having a length of 1 ms mayinclude 2^(μ) slots. In this case, the length of each slot is 2^(−μ) ms.Numbers from 0 to 2^(μ)−1 may be respectively allocated to 2^(μ) slotswithin one wireless frame. In addition, numbers from 0 to 10*2^(μ)−1 maybe respectively allocated to slots within one subframe. The timeresource may be distinguished by at least one of a wireless frame number(also referred to as a wireless frame index), a subframe number (alsoreferred to as a subframe number), and a slot number (or a slot index).

FIG. 2 illustrates an example of a downlink (DL)/uplink (UL) slotstructure in a wireless communication system. In particular, FIG. 2shows the structure of the resource grid of the 3GPP NR system.

There is one resource grid per antenna port. Referring to FIG. 2 , aslot includes a plurality of orthogonal frequency division multiplexing(OFDM) symbols in a time domain and includes a plurality of resourceblocks (RBs) in a frequency domain. An OFDM symbol also means one symbolsection. Unless otherwise specified, OFDM symbols may be referred tosimply as symbols. One RB includes 12 consecutive subcarriers in thefrequency domain. Referring to FIG. 2 , a signal transmitted from eachslot may be represented by a resource grid including N^(size,μ)_(grid,x)*N^(RB) _(sc) subcarriers, and N^(slot) _(symb) OFDM symbols.Here, x=DL when the signal is a DL signal, and x=UL when the signal isan UL signal. N^(size,μ) _(grid,x) represents the number of resourceblocks (RBs) according to the subcarrier spacing constituent μ (x is DLor UL), and N^(slot) _(symb) represents the number of OFDM symbols in aslot. N^(RB) _(sc) is the number of subcarriers constituting one RB andN^(RB) _(sc)=12. An OFDM symbol may be referred to as a cyclic shiftOFDM (CP-OFDM) symbol or a discrete Fourier transform spread OFDM(DFT-s-OFDM) symbol according to a multiple access scheme.

The number of OFDM symbols included in one slot may vary according tothe length of a cyclic prefix (CP). For example, in the case of a normalCP, one slot includes 14 OFDM symbols, but in the case of an extendedCP, one slot may include 12 OFDM symbols. In a specific embodiment, theextended CP can only be used at 60 kHz subcarrier spacing. In FIG. 2 ,for convenience of description, one slot is configured with 14 OFDMsymbols by way of example, but embodiments of the present disclosure maybe applied in a similar manner to a slot having a different number ofOFDM symbols. Referring to FIG. 2 , each OFDM symbol includes N^(size,μ)_(grid,x)*N^(RB) _(sc) subcarriers in the frequency domain. The type ofsubcarrier may be divided into a data subcarrier for data transmission,a reference signal subcarrier for transmission of a reference signal,and a guard band. The carrier frequency is also referred to as thecenter frequency (fc).

One RB may be defined by N^(RB) _(sc) (e. g., 12) consecutivesubcarriers in the frequency domain. For reference, a resourceconfigured with one OFDM symbol and one subcarrier may be referred to asa resource element (RE) or a tone. Therefore, one RB can be configuredwith N^(slot) _(symb)*N^(RB) _(sc) resource elements. Each resourceelement in the resource grid can be uniquely defined by a pair ofindexes (k, l) in one slot. k may be an index assigned from 0 toN^(size,μ) _(grid, x)*N^(RB) _(sc)−1 in the frequency domain, and l maybe an index assigned from 0 to N^(slot) _(symb)−1 in the time domain.

In order for the UE to receive a signal from the base station or totransmit a signal to the base station, the time/frequency of the UE maybe synchronized with the time/frequency of the base station. This isbecause when the base station and the UE are synchronized, the UE candetermine the time and frequency parameters necessary for demodulatingthe DL signal and transmitting the UL signal at the correct time.

Each symbol of a radio frame used in a time division duplex (TDD) or anunpaired spectrum may be configured with at least one of a DL symbol, anUL symbol, and a flexible symbol. A radio frame used as a DL carrier ina frequency division duplex (FDD) or a paired spectrum may be configuredwith a DL symbol or a flexible symbol, and a radio frame used as a ULcarrier may be configured with a UL symbol or a flexible symbol. In theDL symbol, DL transmission is possible, but UL transmission isimpossible. In the UL symbol, UL transmission is possible, but DLtransmission is impossible. The flexible symbol may be determined to beused as a DL or an UL according to a signal.

Information on the type of each symbol, i.e., information representingany one of DL symbols, UL symbols, and flexible symbols, may beconfigured with a cell-specific or common radio resource control (RRC)signal. In addition, information on the type of each symbol mayadditionally be configured with a UE-specific or dedicated RRC signal.The base station informs, by using cell-specific RRC signals, i) theperiod of cell-specific slot configuration, ii) the number of slots withonly DL symbols from the beginning of the period of cell-specific slotconfiguration, iii) the number of DL symbols from the first symbol ofthe slot immediately following the slot with only DL symbols, iv) thenumber of slots with only UL symbols from the end of the period of cellspecific slot configuration, and v) the number of UL symbols from thelast symbol of the slot immediately before the slot with only the ULsymbol. Here, symbols not configured with any one of a UL symbol and aDL symbol are flexible symbols.

When the information on the symbol type is configured with theUE-specific RRC signal, the base station may signal whether the flexiblesymbol is a DL symbol or an UL symbol in the cell-specific RRC signal.In this case, the UE-specific RRC signal can not change a DL symbol or aUL symbol configured with the cell-specific RRC signal into anothersymbol type. The UE-specific RRC signal may signal the number of DLsymbols among the N^(slot) _(symb) symbols of the corresponding slot foreach slot, and the number of UL symbols among the N^(slot) _(symb)symbols of the corresponding slot. In this case, the DL symbol of theslot may be continuously configured with the first symbol to the i-thsymbol of the slot. In addition, the UL symbol of the slot may becontinuously configured with the j-th symbol to the last symbol of theslot (where i<j). In the slot, symbols not configured with any one of aUL symbol and a DL symbol are flexible symbols.

FIG. 3 is a diagram for explaining a physical channel used in a 3GPPsystem (e.g., NR) and a typical signal transmission method using thephysical channel.

If the power of the UE is turned on or the UE camps on a new cell, theUE performs an initial cell search (S101). Specifically, the UE maysynchronize with the BS in the initial cell search. For this, the UE mayreceive a primary synchronization signal (PSS) and a secondarysynchronization signal (SSS) from the base station to synchronize withthe base station, and obtain information such as a cell ID. Thereafter,the UE can receive the physical broadcast channel from the base stationand obtain the broadcast information in the cell.

Upon completion of the initial cell search, the UE receives a physicaldownlink shared channel (PDSCH) according to the physical downlinkcontrol channel (PDCCH) and information in the PDCCH, so that the UE canobtain more specific system information than the system informationobtained through the initial cell search (S102). Here, the systeminformation received by the UE is cell-common system information for theUE to properly operate at the physical layer in Radio Resource Control(RRC), and is referred to as remaining system information (RSMI) orsystem information block (SIB) 1.

When the UE initially accesses the base station or does not have radioresources for signal transmission (when the UE is in RRC_IDLE mode), theUE may perform a random access procedure on the base station (operationsS103 to S106). First, the UE can transmit a preamble through a physicalrandom access channel (PRACH) (S103) and receive a response message forthe preamble from the base station through the PDCCH and thecorresponding PDSCH (S104). When a valid random access response messageis received by the UE, the UE transmits data including the identifier ofthe UE and the like to the base station through a physical uplink sharedchannel (PUSCH) indicated by the UL grant transmitted through the PDCCHfrom the base station (S105). Next, the UE waits for reception of thePDCCH as an indication of the base station for collision resolution. Ifthe UE successfully receives the PDCCH through the identifier of the UE(S106), the random access process is terminated. During the randomaccess process, the UE may obtain UE-specific system informationnecessary for the UE to properly operate at the physical layer in theRRC layer. When the UE obtains UE-specific system information from theRRC layer, the UE enters the RRC_CONNECTED mode.

The RRC layer is used for message generation and management for controlbetween a UE and a radio access network (RAN). More specifically, in theRRC layer, the base station and the UE may perform broadcasting of cellsystem information, delivery management of paging messages, mobilitymanagement and handover, measurement report and control thereof, UEcapability management, and storage management including existingmanagement necessary for all UEs in the cell. In general, since theupdate of the signal (hereinafter, referred to as RRC signal)transmitted from the RRC layer is longer than the transmission/receptionperiod (i.e., transmission time interval, TTI) in the physical layer,the RRC signal may be maintained unchanged for a long period.

After the above-described procedure, the UE receives PDCCH/PDSCH (S107)and transmits a physical uplink shared channel (PUSCH)/physical uplinkcontrol channel (PUCCH) (S108) as a general UL/DL signal transmissionprocedure. In particular, the UE may receive downlink controlinformation (DCI) through the PDCCH. The DCI may include controlinformation such as resource allocation information for the UE. Also,the format of the DCI may vary depending on the intended use. The uplinkcontrol information (UCI) that the UE transmits to the base stationthrough UL includes a DL/UL ACK/NACK signal, a channel quality indicator(CQI), a precoding matrix index (PMI), a rank indicator (RI), and thelike. Here, the CQI, PMI, and RI may be included in channel stateinformation (CSI). In the 3GPP NR system, the UE may transmit controlinformation such as HARQ-ACK and CSI described above through the PUSCHand/or PUCCH.

FIG. 4 illustrates an SS/PBCH block for initial cell access in a 3/GPPNR system.

When the power is turned on or wanting to access a new cell, the UE mayobtain time and frequency synchronization with the cell and perform aninitial cell search procedure. The UE may detect a physical cellidentity NcellID of the cell during a cell search procedure. For this,the UE may receive a synchronization signal, for example, a primarysynchronization signal (PSS) and a secondary synchronization signal(SSS), from a base station, and synchronize with the base station. Inthis case, the UE can obtain information such as a cell identity (ID).

Referring to FIG. 4 a, a synchronization signal (SS) will be describedin more detail. The synchronization signal can be classified into PSSand SSS. The PSS may be used to obtain time domain synchronizationand/or frequency domain synchronization, such as OFDM symbolsynchronization and slot synchronization. The SSS can be used to obtainframe synchronization and cell group ID. Referring to FIG. 4 a and Table1, the SS/PBCH block can be configured with consecutive 20 RBs (=240subcarriers) in the frequency axis, and can be configured withconsecutive 4 OFDM symbols in the time axis. In this case, in theSS/PBCH block, the PSS is transmitted in the first OFDM symbol and theSSS is transmitted in the third OFDM symbol through the 56th to 182thsubcarriers. Here, the lowest subcarrier index of the SS/PBCH block isnumbered from 0. In the first OFDM symbol in which the PSS istransmitted, the base station does not transmit a signal through theremaining subcarriers, i.e., 0th to 55th and 183th to 239th subcarriers.In addition, in the third OFDM symbol in which the SSS is transmitted,the base station does not transmit a signal through 48th to 55th and183th to 191th subcarriers. The base station transmits a physicalbroadcast channel (PBCH) through the remaining RE except for the abovesignal in the SS/PBCH block.

TABLE 1 OFDM symbol number l Subcarrier number k Channel relative to thestart relative to the start or signal of an SS/PBCH block of an SS/PBCHblock PSS 0 56, 57, . . . , 182 SSS 2 56, 57, . . . , 182 Set to 0 0 0,1, . . . , 55, 183, 184, . . . , 239 2 48, 49, . . . , 55, 183, 184, . .. , 191 PBCH 1, 3 0, 1, . . . , 239 2 0, 1, . . . , 47, 192, 193, . . ., 239 DM-RS for 1, 3 0 + v, 4 + v, 8 + PBCH v, . . . , 236 + v 2 0 + v,4 + v, 8 + v, . . . , 44 + v 192 + v, 196 + v, . . . , 236 + v

The SS allows a total of 1008 unique physical layer cell IDs to begrouped into 336 physical-layer cell-identifier groups, each groupincluding three unique identifiers, through a combination of three PSSsand SSSs, specifically, such that each physical layer cell ID is to beonly a part of one physical-layer cell-identifier group. Therefore, thephysical layer cell ID N^(cell) _(ID)=3N⁽¹⁾ _(ID)+N⁽²⁾ _(ID) can beuniquely defined by the index N⁽¹⁾ _(ID) ranging from 0 to 335indicating a physical-layer cell-identifier group and the index N⁽²⁾_(ID) ranging from 0 to 2 indicating a physical-layer identifier in thephysical-layer cell-identifier group. The UE may detect the PSS andidentify one of the three unique physical-layer identifiers. Inaddition, the UE can detect the SSS and identify one of the 336 physicallayer cell IDs associated with the physical-layer identifier. In thiscase, the sequence dsss(n) of the PSS is as follows.

d _(PSS)(n)=1−2x(m)

m=(n+43N _(ID) ⁽²⁾)mod 127

0≤n<127

Here, x(i+7)=(x(i+4)+x(i))mod 2 and is given as,

[x(6) x(5) x(4) x(3) x(2) x(1) x(0)]=[1 1 1 0 1 1 0]

Further, the sequence d_(SSS)(n) of the SSS is as follows.

d_(SSS)(n) = [1 − 2x₀((n + m₀)mod127)][1 − 2x₁((n + m₁)mod127)]$m_{0} = {{15\left\lfloor \frac{N_{ID}^{(1)}}{112} \right\rfloor} + {5N_{ID}^{(2)}}}$m₁ = N_(ID)⁽¹⁾mod112 0 ≤ n < 127 ${Here},\begin{matrix}{{x_{0}\left( {i + 7} \right)} = {\left( {{x_{0}\left( {i + 4} \right)} + {x_{0}(i)}} \right){mod}2}} \\{{x_{1}\left( {i + 7} \right)} = {\left( {{x_{1}\left( {i + 1} \right)} + {x_{1}(i)}} \right){mod}2}}\end{matrix}$

and is given as,

$\begin{bmatrix}{x_{0}(6)} & {x_{0}(5)} & {x_{0}(4)} & {x_{0}(3)} & {x_{0}(2)} & {x_{0}(1)} & {x_{0}(0)}\end{bmatrix} = \begin{bmatrix}0 & 0 & 0 & 0 & 0 & 0 & 1\end{bmatrix}$ $\begin{bmatrix}{x_{1}(6)} & {x_{1}(5)} & {x_{1}(4)} & {x_{1}(3)} & {x_{1}(2)} & {x_{1}(1)} & {x_{1}(0)}\end{bmatrix} = \begin{bmatrix}0 & 0 & 0 & 0 & 0 & 0 & 1\end{bmatrix}$

A radio frame with a 10 ms length may be divided into two half frameswith a 5 ms length.

Referring to FIG. 4 b, a description will be made of a slot in whichSS/PBCH blocks are transmitted in each half frame. A slot in which theSS/PBCH block is transmitted may be any one of the cases A, B, C, D, andE. In the case A, the subcarrier spacing is 15 kHz and the starting timepoint of the SS/PBCH block is the ({2, 8}+14*n)-th symbol. In this case,n=0 or 1 at a carrier frequency of 3 GHz or less. In addition, it may ben=0, 1, 2, 3 at carrier frequencies above 3 GHz and below 6 GHz. In thecase B, the subcarrier spacing is kHz and the starting time point of theSS/PBCH block is {4, 8, 16, 20}+28*n. In this case, n=0 at a carrierfrequency of 3 GHz or less. In addition, it may be n=0, 1 at carrierfrequencies above 3 GHz and below 6 GHz. In the case C, the subcarrierspacing is 30 kHz and the starting time point of the SS/PBCH block isthe ({2, 8}+14*n)-th symbol. In this case, n=0 or 1 at a carrierfrequency of 3 GHz or less. In addition, it may be n=0, 1, 2, 3 atcarrier frequencies above 3 GHz and below 6 GHz. In the case D, thesubcarrier spacing is 120 kHz and the starting time point of the SS/PBCHblock is the ({4, 8, 16, 20}+28*n)-th symbol. In this case, at a carrierfrequency of 6 GHz or more, n=0, 1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 13,15, 16, 17, 18. In the case E, the subcarrier spacing is 240 kHz and thestarting time point of the SS/PBCH block is the ({8, 12, 16, 20, 32, 36,40, 44}+56*n)-th symbol. In this case, at a carrier frequency of 6 GHzor more, n=0, 1, 2, 3, 5, 6, 7, 8.

FIG. 5 illustrates a procedure for transmitting control information anda control channel in a 3GPP NR system. Referring to FIG. 5 a, the basestation may add a cyclic redundancy check (CRC) masked (e.g., an XORoperation) with a radio network temporary identifier (RNTI) to controlinformation (e.g., downlink control information (DCI)) (S202). The basestation may scramble the CRC with an RNTI value determined according tothe purpose/target of each control information. The common RNTI used byone or more UEs can include at least one of a system information RNTI(SI-RNTI), a paging RNTI (P-RNTI), a random access RNTI (RA-RNTI), and atransmit power control RNTI (TPC-RNTI). In addition, the UE-specificRNTI may include at least one of a cell temporary RNTI (C-RNTI), and theCS-RNTI. Thereafter, the base station may perform rate-matching (S206)according to the amount of resource(s) used for PDCCH transmission afterperforming channel encoding (e.g., polar coding) (S204). Thereafter, thebase station may multiplex the DCI(s) based on the control channelelement (CCE) based PDCCH structure (S208). In addition, the basestation may apply an additional process (S210) such as scrambling,modulation (e.g., QPSK), interleaving, and the like to the multiplexedDCI(s), and then map the DCI(s) to the resource to be transmitted. TheCCE is a basic resource unit for the PDCCH, and one CCE may include aplurality (e.g., six) of resource element groups (REGs). One REG may beconfigured with a plurality (e.g., 12) of REs. The number of CCEs usedfor one PDCCH may be defined as an aggregation level. In the 3GPP NRsystem, an aggregation level of 1, 2, 4, 8, or 16 may be used. FIG. 5 bis a diagram related to a CCE aggregation level and the multiplexing ofa PDCCH and illustrates the type of a CCE aggregation level used for onePDCCH and CCE(s) transmitted in the control area according thereto.

FIG. 6 illustrates a control resource set (CORESET) in which a physicaldownlink control channel (PUCCH) may be transmitted in a 3GPP NR system.

The CORESET is a time-frequency resource in which PDCCH, that is, acontrol signal for the UE, is transmitted. In addition, a search spaceto be described later may be mapped to one CORESET. Therefore, the UEmay monitor the time-frequency domain designated as CORESET instead ofmonitoring all frequency bands for PDCCH reception, and decode the PDCCHmapped to CORESET. The base station may configure one or more CORESETsfor each cell to the UE. The CORESET may be configured with up to threeconsecutive symbols on the time axis. In addition, the CORESET may beconfigured in units of six consecutive PRBs on the frequency axis. Inthe embodiment of FIG. 5 , CORESET #1 is configured with consecutivePRBs, and CORESET #2 and CORESET #3 are configured with discontinuousPRBs. The CORESET can be located in any symbol in the slot. For example,in the embodiment of FIG. 5 , CORESET #1 starts at the first symbol ofthe slot, CORESET #2 starts at the fifth symbol of the slot, and CORESET#9 starts at the ninth symbol of the slot.

FIG. 7 illustrates a method for setting a PUCCH search space in a 3GPPNR system.

In order to transmit the PDCCH to the UE, each CORESET may have at leastone search space. In the embodiment of the present disclosure, thesearch space is a set of all time-frequency resources (hereinafter,PDCCH candidates) through which the PDCCH of the UE is capable of beingtransmitted. The search space may include a common search space that theUE of the 3GPP NR is required to commonly search and a Terminal-specificor a UE-specific search space that a specific UE is required to search.In the common search space, UE may monitor the PDCCH that is set so thatall UEs in the cell belonging to the same base station commonly search.In addition, the UE-specific search space may be set for each UE so thatUEs monitor the PDCCH allocated to each UE at different search spaceposition according to the UE. In the case of the UE-specific searchspace, the search space between the UEs may be partially overlapped andallocated due to the limited control area in which the PDCCH may beallocated. Monitoring the PDCCH includes blind decoding for PDCCHcandidates in the search space. When the blind decoding is successful,it may be expressed that the PDCCH is (successfully) detected/receivedand when the blind decoding fails, it may be expressed that the PDCCH isnot detected/not received, or is not successfully detected/received.

For convenience of explanation, a PDCCH scrambled with a group common(GC) RNTI previously known to UEs so as to transmit DL controlinformation to the one or more UEs is referred to as a group common (GC)PDCCH or a common PDCCH. In addition, a PDCCH scrambled with aspecific-terminal RNTI that a specific UE already knows so as totransmit UL scheduling information or DL scheduling information to thespecific UE is referred to as a specific-UE PDCCH. The common PDCCH maybe included in a common search space, and the UE-specific PDCCH may beincluded in a common search space or a UE-specific PDCCH.

The base station may signal each UE or UE group through a PDCCH aboutinformation (i.e., DL Grant) related to resource allocation of a pagingchannel (PCH) and a downlink-shared channel (DL-SCH) that are atransmission channel or information (i.e., UL grant) related to resourceallocation of a uplink-shared channel (UL-SCH) and a hybrid automaticrepeat request (HARQ). The base station may transmit the PCH transportblock and the DL-SCH transport block through the PDSCH. The base stationmay transmit data excluding specific control information or specificservice data through the PDSCH. In addition, the UE may receive dataexcluding specific control information or specific service data throughthe PDSCH.

The base station may include, in the PDCCH, information on to which UE(one or a plurality of UEs) PDSCH data is transmitted and how the PDSCHdata is to be received and decoded by the corresponding UE, and transmitthe PDCCH. For example, it is assumed that the DCI transmitted on aspecific PDCCH is CRC masked with an RNTI of “A”, and the DCI indicatesthat PDSCH is allocated to a radio resource (e.g., frequency location)of “B” and indicates transmission format information (e.g., transportblock size, modulation scheme, coding information, etc.) of “C”. The UEmonitors the PDCCH using the RNTI information that the UE has. In thiscase, if there is a UE which performs blind decoding the PDCCH using the“A” RNTI, the UE receives the PDCCH, and receives the PDSCH indicated by“B” and “C” through the received PDCCH information.

Table 2 shows an embodiment of a physical uplink control channel (PUCCH)used in a wireless communication system.

TABLE 2 PUCCH format Length in OFDM symbols Number of bits 0 1-2  ≤2 14-14 ≤2 2 1-2  >2 3 4-14 >2 4 4-14 >2

PUCCH may be used to transmit the following UL control information(UCI).

-   -   Scheduling Request (SR): Information used for requesting a UL        UL-SCH resource.    -   HARQ-ACK: A Response to PDCCH (indicating DL SPS release) and/or        a response to DL transport block (TB) on PDSCH. HARQ-ACK        indicates whether information transmitted on the PDCCH or PDSCH        is received. The HARQ-ACK response includes positive ACK (simply        ACK), negative ACK (hereinafter NACK), Discontinuous        Transmission (DTX), or NACK/DTX. Here, the term HARQ-ACK is used        mixed with HARQ-ACK/NACK and ACK/NACK. In general, ACK may be        represented by bit value 1 and NACK may be represented by bit        value 0.    -   Channel State Information (CSI): Feedback information on the DL        channel. The UE generates it based on the CSI-Reference Signal        (RS) transmitted by the base station. Multiple Input Multiple        Output (MIMO)-related feedback information includes a Rank        Indicator (RI) and a Precoding Matrix Indicator (PMI). CSI can        be divided into CSI part 1 and CSI part 2 according to the        information indicated by CSI.

In the 3GPP NR system, five PUCCH formats may be used to support variousservice scenarios, various channel environments, and frame structures.

PUCCH format 0 is a format capable of transmitting 1-bit or 2-bitHARQ-ACK information or SR. PUCCH format 0 can be transmitted throughone or two OFDM symbols on the time axis and one RB on the frequencyaxis. When PUCCH format 0 is transmitted in two OFDM symbols, the samesequence to the two symbols may be transmitted through different RBs. Inthis case, the sequence may be a cyclic shift (CS) sequence from thebase sequence used for PUCCH format 0. Through this, the UE can obtain afrequency diversity gain. Specifically, the UE may determine a cyclicshift (CS) value m_(cs) according to the M_(bit) bit UCI (M_(bit)=1 or2). In addition, a sequence in which a base sequence of length 12 iscyclically shifted based on a predetermined CS value m_(cs) may bemapped to 1 OFDM symbol and 12 REs of 1 RB and transmitted. When thenumber of cyclic shifts available to the UE is 12 and M_(bit)=1, 1 bitUCI 0 and 1 may be mapped to two cyclic shifted sequences having adifference of 6 cyclic shift values, respectively. In addition, whenM_(bit)=2, 2 bits UCI 00, 01, 11, and 10 may be mapped to four cyclicshifted sequences in which the difference in cyclic shift values is 3,respectively.

PUCCH format 1 may deliver 1-bit or 2-bit HARQ-ACK information or SR.PUCCH format 1 may be transmitted through consecutive OFDM symbols onthe time axis and one PRB on the frequency axis. Here, the number ofOFDM symbols occupied by PUCCH format 1 may be one of 4 to 14. Morespecifically, UCI, which is M_(bit)=1, may be BPSK-modulated. The UE maymodulate UCI, which is M_(bit)=2, with quadrature phase shift keying(QPSK). A signal is obtained by multiplying a modulated complex valuedsymbol d(0) by a sequence of length 12. In this case, the sequence maybe a base sequence used for PUCCH format 0. The UE spreads theeven-numbered OFDM symbols to which PUCCH format 1 is allocated throughthe time axis orthogonal cover code (OCC) to transmit the obtainedsignal. PUCCH format 1 determines the maximum number of different UEsmultiplexed in the one RB according to the length of the OCC to be used.A demodulation reference signal (DMRS) may be spread with OCC and mappedto the odd-numbered OFDM symbols of PUCCH format 1.

PUCCH format 2 may deliver UCI exceeding 2 bits. PUCCH format 2 may betransmitted through one or two OFDM symbols on the time axis and one ora plurality of RBs on the frequency axis. When PUCCH format 2 istransmitted in two OFDM symbols, the sequences which are transmitted indifferent RBs through the two OFDM symbols may be same each other. Here,the sequence may be a plurality of modulated complex valued symbolsd(0), . . . , d(M_(symbol)−1). Here, M_(symbol) may be M_(bit)/2.Through this, the UE may obtain a frequency diversity gain. Morespecifically, M_(bit) bit UCI (M_(bit)>2) is bit-level scrambled, QPSKmodulated, and mapped to RB(s) of one or two OFDM symbol(s). Here, thenumber of RBs may be one of 1 to 16.

PUCCH format 3 or PUCCH format 4 may deliver UCI exceeding 2 bits. PUCCHformat 3 or PUCCH format 4 may be transmitted through consecutive OFDMsymbols on the time axis and one PRB on the frequency axis. The numberof OFDM symbols occupied by PUCCH format 3 or PUCCH format 4 may be oneof 4 to 14. Specifically, the UE modulates M_(bit) bits UCI (Mbit>2)with π/2-Binary Phase Shift Keying (BPSK) or QPSK to generate a complexvalued symbol d(0) to d(M_(symb)−1). Here, when using π/2-BPSK,M_(symb)=M_(bit), and when using QPSK, M_(symb)=M_(bit)/2. The UE maynot apply block-unit spreading to the PUCCH format 3. However, the UEmay apply block-unit spreading to one RB (i.e., 12 subcarriers) usingPreDFT-OCC of a length of 12 such that PUCCH format 4 may have two orfour multiplexing capacities. The UE performs transmit precoding (orDFT-precoding) on the spread signal and maps it to each RE to transmitthe spread signal.

In this case, the number of RBs occupied by PUCCH format 2, PUCCH format3, or PUCCH format 4 may be determined according to the length andmaximum code rate of the UCI transmitted by the UE. When the UE usesPUCCH format 2, the UE may transmit HARQ-ACK information and CSIinformation together through the PUCCH. When the number of RBs that theUE may transmit is greater than the maximum number of RBs that PUCCHformat 2, or PUCCH format 3, or PUCCH format 4 may use, the UE maytransmit only the remaining UCI information without transmitting someUCI information according to the priority of the UCI information.

PUCCH format 1, PUCCH format 3, or PUCCH format 4 may be configuredthrough the RRC signal to indicate frequency hopping in a slot. Whenfrequency hopping is configured, the index of the RB to be frequencyhopped may be configured with an RRC signal. When PUCCH format 1, PUCCHformat 3, or PUCCH format 4 is transmitted through N OFDM symbols on thetime axis, the first hop may have floor (N/2) OFDM symbols and thesecond hop may have ceiling (N/2) OFDM symbols.

PUCCH format 1, PUCCH format 3, or PUCCH format 4 may be configured tobe repeatedly transmitted in a plurality of slots. In this case, thenumber K of slots in which the PUCCH is repeatedly transmitted may beconfigured by the RRC signal. The repeatedly transmitted PUCCHs muststart at an OFDM symbol of the constant position in each slot, and havethe constant length. When one OFDM symbol among OFDM symbols of a slotin which a UE should transmit a PUCCH is indicated as a DL symbol by anRRC signal, the UE may not transmit the PUCCH in a corresponding slotand delay the transmission of the PUCCH to the next slot to transmit thePUCCH.

Meanwhile, in the 3GPP NR system, the UE may performtransmission/reception using a bandwidth less than or equal to thebandwidth of the carrier (or cell). To this end, the UE may beconfigured with a bandwidth part (BWP) consisting of a continuousbandwidth of a portion of the bandwidth of the carrier. A UE operatingaccording to TDD or operating in an unpaired spectrum may receive up tofour DL/UL BWP pairs for one carrier (or cell). In addition, the UE mayactivate one DL/UL BWP pair. A UE operating according to FDD oroperating in a paired spectrum may receive up to 4 DL BWPs on a downlinkcarrier (or cell) and up to 4 UL BWPs on an uplink carrier (or cell).The UE may activate one DL BWP and UL BWP for each carrier (or cell).The UE may not receive or transmit in time-frequency resources otherthan the activated BWP. The activated BWP may be referred to as anactive BWP.

The base station may indicate an activated BWP among the BWPs configuredby the UE through downlink control information (DCI). The BWP indicatedthrough DCI is activated, and other configured BWP(s) are deactivated.In a carrier (or cell) operating in TDD, the base station may include abandwidth part indicator (BPI) indicating the BWP activated in the DCIscheduling the PDSCH or PUSCH to change the DL/UL BWP pair of the UE.The UE may receive a DCI scheduling a PDSCH or a PUSCH and may identifya DL/UL BWP pair activated based on the BPI. In the case of a downlinkcarrier (or cell) operating in FDD, the base station may include a BPIindicating the activated BWP in the DCI scheduling the PDSCH to changethe DL BWP of the UE. In the case of an uplink carrier (or cell)operating in FDD, the base station may include a BPI indicating theactivated BWP in the DCI scheduling the PUSCH to change the UL BWP ofthe UE.

FIG. 8 is a conceptual diagram illustrating carrier aggregation.

The carrier aggregation is a method in which the UE uses a plurality offrequency blocks or cells (in the logical sense) configured with ULresources (or component carriers) and/or DL resources (or componentcarriers) as one large logical frequency band in order for a wirelesscommunication system to use a wider frequency band. One componentcarrier may also be referred to as a term called a Primary cell (PCell)or a Secondary cell (SCell), or a Primary SCell (PScell). However,hereinafter, for convenience of description, the term “componentcarrier” is used.

Referring to FIG. 8 , as an example of a 3GPP NR system, the entiresystem band may include up to 16 component carriers, and each componentcarrier may have a bandwidth of up to 400 MHz. The component carrier mayinclude one or more physically consecutive subcarriers. Although it isshown in FIG. 8 that each of the component carriers has the samebandwidth, this is merely an example, and each component carrier mayhave a different bandwidth. Also, although each component carrier isshown as being adjacent to each other in the frequency axis, thedrawings are shown in a logical concept, and each component carrier maybe physically adjacent to one another, or may be spaced apart.

Different center frequencies may be used for each component carrier.Also, one common center frequency may be used in physically adjacentcomponent carriers. Assuming that all the component carriers arephysically adjacent in the embodiment of FIG. 8 , center frequency A maybe used in all the component carriers. Further, assuming that therespective component carriers are not physically adjacent to each other,center frequency A and the center frequency B can be used in each of thecomponent carriers.

When the total system band is extended by carrier aggregation, thefrequency band used for communication with each UE can be defined inunits of a component carrier. UE A may use 100 MHz, which is the totalsystem band, and performs communication using all five componentcarriers. UEs B₁˜B₅ can use only a 20 MHz bandwidth and performcommunication using one component carrier. UEs C₁ and C₂ may use a 40MHz bandwidth and perform communication using two component carriers,respectively. The two component carriers may be logically/physicallyadjacent or non-adjacent. UE C₁ represents the case of using twonon-adjacent component carriers, and UE C₂ represents the case of usingtwo adjacent component carriers.

FIG. 9 is a drawing for explaining signal carrier communication andmultiple carrier communication. Particularly, FIG. 9(a) shows a singlecarrier subframe structure and FIG. 9(b) shows a multi-carrier subframestructure.

Referring to FIG. 9(a), in an FDD mode, a general wireless communicationsystem may perform data transmission or reception through one DL bandand one UL band corresponding thereto. In another specific embodiment,in a TDD mode, the wireless communication system may divide a radioframe into a UL time unit and a DL time unit in a time domain, andperform data transmission or reception through a UL/DL time unit.Referring to FIG. 9(b), three 20 MHz component carriers (CCs) can beaggregated into each of UL and DL, so that a bandwidth of 60 MHz can besupported. Each CC may be adjacent or non-adjacent to one another in thefrequency domain. FIG. 9(b) shows a case where the bandwidth of the ULCC and the bandwidth of the DL CC are the same and symmetric, but thebandwidth of each CC can be determined independently. In addition,asymmetric carrier aggregation with different number of UL CCs and DLCCs is possible. A DL/UL CC allocated/configured to a specific UEthrough RRC may be called as a serving DL/UL CC of the specific UE.

The base station may perform communication with the UE by activatingsome or all of the serving CCs of the UE or deactivating some CCs. Thebase station can change the CC to be activated/deactivated, and changethe number of CCs to be activated/deactivated. If the base stationallocates a CC available for the UE as to be cell-specific orUE-specific, at least one of the allocated CCs can be deactivated,unless the CC allocation for the UE is completely reconfigured or the UEis handed over. One CC that is not deactivated by the UE is called as aPrimary CC (PCC) or a primary cell (PCell), and a CC that the basestation can freely activate/deactivate is called as a Secondary CC (SCC)or a secondary cell (SCell).

Meanwhile, 3GPP NR uses the concept of a cell to manage radio resources.A cell is defined as a combination of DL resources and UL resources,that is, a combination of DL CC and UL CC. A cell may be configured withDL resources alone, or a combination of DL resources and UL resources.When the carrier aggregation is supported, the linkage between thecarrier frequency of the DL resource (or DL CC) and the carrierfrequency of the UL resource (or UL CC) may be indicated by systeminformation. The carrier frequency refers to the center frequency ofeach cell or CC. A cell corresponding to the PCC is referred to as aPCell, and a cell corresponding to the SCC is referred to as an SCell.The carrier corresponding to the PCell in the DL is the DL PCC, and thecarrier corresponding to the PCell in the UL is the UL PCC. Similarly,the carrier corresponding to the SCell in the DL is the DL SCC and thecarrier corresponding to the SCell in the UL is the UL SCC. According toUE capability, the serving cell(s) may be configured with one PCell andzero or more SCells. In the case of UEs that are in the RRC_CONNECTEDstate but not configured for carrier aggregation or that do not supportcarrier aggregation, there is only one serving cell configured only withPCell.

As mentioned above, the term “cell” used in carrier aggregation isdistinguished from the term “cell” which refers to a certaingeographical area in which a communication service is provided by onebase station or one antenna group. That is, one component carrier mayalso be referred to as a scheduling cell, a scheduled cell, a primarycell (PCell), a secondary cell (SCell), or a primary SCell (PScell).However, in order to distinguish between a cell referring to a certaingeographical area and a cell of carrier aggregation, in the presentdisclosure, a cell of a carrier aggregation is referred to as a CC, anda cell of a geographical area is referred to as a cell.

FIG. 10 is a diagram showing an example in which a cross carrierscheduling technique is applied. When cross carrier scheduling is set,the control channel transmitted through the first CC may schedule a datachannel transmitted through the first CC or the second CC using acarrier indicator field (CIF). The CIF is included in the DCI. In otherwords, a scheduling cell is set, and the DL grant/UL grant transmittedin the PDCCH area of the scheduling cell schedules the PDSCH/PUSCH ofthe scheduled cell. That is, a search area for the plurality ofcomponent carriers exists in the PDCCH area of the scheduling cell. APCell may be basically a scheduling cell, and a specific SCell may bedesignated as a scheduling cell by an upper layer.

In the embodiment of FIG. 10 , it is assumed that three DL CCs aremerged. Here, it is assumed that DL component carrier #0 is DL PCC (orPCell), and DL component carrier #1 and DL component carrier #2 are DLSCCs (or SCell). In addition, it is assumed that the DL PCC is set tothe PDCCH monitoring CC. When cross-carrier scheduling is not configuredby UE-specific (or UE-group-specific or cell-specific) higher layersignaling, a CIF is disabled, and each DL CC can transmit only a PDCCHfor scheduling its PDSCH without the CIF according to an NR PDCCH rule(non-cross-carrier scheduling, self-carrier scheduling). Meanwhile, ifcross-carrier scheduling is configured by UE-specific (orUE-group-specific or cell-specific) higher layer signaling, a CIF isenabled, and a specific CC (e.g., DL PCC) may transmit not only thePDCCH for scheduling the PDSCH of the DL CC A using the CIF but also thePDCCH for scheduling the PDSCH of another CC (cross-carrier scheduling).On the other hand, a PDCCH is not transmitted in another DL CC.Accordingly, the UE monitors the PDCCH not including the CIF to receivea self-carrier scheduled PDSCH depending on whether the cross-carrierscheduling is configured for the UE, or monitors the PDCCH including theCIF to receive the cross-carrier scheduled PDSCH.

On the other hand, FIGS. 9 and 10 illustrate the subframe structure ofthe 3GPP LTE-A system, and the same or similar configuration may beapplied to the 3GPP NR system. However, in the 3GPP NR system, thesubframes of FIGS. 9 and 10 may be replaced with slots.

FIG. 11 is a block diagram showing the configurations of a UE and a basestation according to an embodiment of the present disclosure. In anembodiment of the present disclosure, the UE may be implemented withvarious types of wireless communication devices or computing devicesthat are guaranteed to be portable and mobile. The UE may be referred toas a User Equipment (UE), a Station (STA), a Mobile Subscriber (MS), orthe like. In addition, in an embodiment of the present disclosure, thebase station controls and manages a cell (e.g., a macro cell, a femtocell, a pico cell, etc.) corresponding to a service area, and performsfunctions of a signal transmission, a channel designation, a channelmonitoring, a self diagnosis, a relay, or the like. The base station maybe referred to as next Generation NodeB (gNB) or Access Point (AP).

As shown in the drawing, a UE 100 according to an embodiment of thepresent disclosure may include a processor 110, a communication module120, a memory 130, a user interface 140, and a display unit 150.

First, the processor 110 may execute various instructions or programsand process data within the UE 100. In addition, the processor 110 maycontrol the entire operation including each unit of the UE 100, and maycontrol the transmission/reception of data between the units. Here, theprocessor 110 may be configured to perform an operation according to theembodiments described in the present disclosure. For example, theprocessor 110 may receive slot configuration information, determine aslot configuration based on the slot configuration information, andperform communication according to the determined slot configuration.

Next, the communication module 120 may be an integrated module thatperforms wireless communication using a wireless communication networkand a wireless LAN access using a wireless LAN. For this, thecommunication module 120 may include a plurality of network interfacecards (NICs) such as cellular communication interface cards 121 and 122and an unlicensed band communication interface card 123 in an internalor external form. In the drawing, the communication module 120 is shownas an integral integration module, but unlike the drawing, each networkinterface card can be independently arranged according to a circuitconfiguration or usage.

The cellular communication interface card 121 may transmit or receive aradio signal with at least one of the base station 200, an externaldevice, and a server by using a mobile communication network and providea cellular communication service in a first frequency band based on theinstructions from the processor 110. According to an embodiment, thecellular communication interface card 121 may include at least one NICmodule using a frequency band of less than 6 GHz. At least one NICmodule of the cellular communication interface card 121 mayindependently perform cellular communication with at least one of thebase station 200, an external device, and a server in accordance withcellular communication standards or protocols in the frequency bandsbelow 6 GHz supported by the corresponding NIC module.

The cellular communication interface card 122 may transmit or receive aradio signal with at least one of the base station 200, an externaldevice, and a server by using a mobile communication network and providea cellular communication service in a second frequency band based on theinstructions from the processor 110. According to an embodiment, thecellular communication interface card 122 may include at least one NICmodule using a frequency band of more than 6 GHz. At least one NICmodule of the cellular communication interface card 122 mayindependently perform cellular communication with at least one of thebase station 200, an external device, and a server in accordance withcellular communication standards or protocols in the frequency bands of6 GHz or more supported by the corresponding NIC module.

The unlicensed band communication interface card 123 transmits orreceives a radio signal with at least one of the base station 200, anexternal device, and a server by using a third frequency band which isan unlicensed band, and provides an unlicensed band communicationservice based on the instructions from the processor 110. The unlicensedband communication interface card 123 may include at least one NICmodule using an unlicensed band. For example, the unlicensed band may bea band of 2.4 GHz or 5 GHz. At least one NIC module of the unlicensedband communication interface card 123 may independently or dependentlyperform wireless communication with at least one of the base station200, an external device, and a server according to the unlicensed bandcommunication standard or protocol of the frequency band supported bythe corresponding NIC module.

The memory 130 stores a control program used in the UE 100 and variouskinds of data therefor. Such a control program may include a prescribedprogram required for performing wireless communication with at least oneamong the base station 200, an external device, and a server.

Next, the user interface 140 includes various kinds of input/outputmeans provided in the UE 100. In other words, the user interface 140 mayreceive a user input using various input means, and the processor 110may control the UE 100 based on the received user input. In addition,the user interface 140 may perform an output based on instructions fromthe processor 110 using various kinds of output means.

Next, the display unit 150 outputs various images on a display screen.The display unit 150 may output various display objects such as contentexecuted by the processor 110 or a user interface based on controlinstructions from the processor 110.

In addition, the base station 200 according to an embodiment of thepresent disclosure may include a processor 210, a communication module220, and a memory 230.

First, the processor 210 may execute various instructions or programs,and process internal data of the base station 200. In addition, theprocessor 210 may control the entire operations of units in the basestation 200, and control data transmission and reception between theunits. Here, the processor 210 may be configured to perform operationsaccording to embodiments described in the present disclosure. Forexample, the processor 210 may signal slot configuration and performcommunication according to the signaled slot configuration.

Next, the communication module 220 may be an integrated module thatperforms wireless communication using a wireless communication networkand a wireless LAN access using a wireless LAN. For this, thecommunication module 120 may include a plurality of network interfacecards such as cellular communication interface cards 221 and 222 and anunlicensed band communication interface card 223 in an internal orexternal form. In the drawing, the communication module 220 is shown asan integral integration module, but unlike the drawing, each networkinterface card can be independently arranged according to a circuitconfiguration or usage.

The cellular communication interface card 221 may transmit or receive aradio signal with at least one of the UE 100, an external device, and aserver by using a mobile communication network and provide a cellularcommunication service in the first frequency band based on theinstructions from the processor 210. According to an embodiment, thecellular communication interface card 221 may include at least one NICmodule using a frequency band of less than 6 GHz. The at least one NICmodule of the cellular communication interface card 221 mayindependently perform cellular communication with at least one of the UE100, an external device, and a server in accordance with the cellularcommunication standards or protocols in the frequency bands less than 6GHz supported by the corresponding NIC module.

The cellular communication interface card 222 may transmit or receive aradio signal with at least one of the UE 100, an external device, and aserver by using a mobile communication network and provide a cellularcommunication service in the second frequency band based on theinstructions from the processor 210. According to an embodiment, thecellular communication interface card 222 may include at least one NICmodule using a frequency band of 6 GHz or more. The at least one NICmodule of the cellular communication interface card 222 mayindependently perform cellular communication with at least one of thebase station 100, an external device, and a server in accordance withthe cellular communication standards or protocols in the frequency bands6 GHz or more supported by the corresponding NIC module.

The unlicensed band communication interface card 223 transmits orreceives a radio signal with at least one of the base station 100, anexternal device, and a server by using the third frequency band which isan unlicensed band, and provides an unlicensed band communicationservice based on the instructions from the processor 210. The unlicensedband communication interface card 223 may include at least one NICmodule using an unlicensed band. For example, the unlicensed band may bea band of 2.4 GHz or 5 GHz. At least one NIC module of the unlicensedband communication interface card 223 may independently or dependentlyperform wireless communication with at least one of the UE 100, anexternal device, and a server according to the unlicensed bandcommunication standards or protocols of the frequency band supported bythe corresponding NIC module.

FIG. 11 is a block diagram illustrating the UE 100 and the base station200 according to an embodiment of the present disclosure, and blocksseparately shown are logically divided elements of a device.Accordingly, the aforementioned elements of the device may be mounted ina single chip or a plurality of chips according to the design of thedevice. In addition, a part of the configuration of the UE 100, forexample, a user interface 140, a display unit 150 and the like may beselectively provided in the UE 100. In addition, the user interface 140,the display unit 150 and the like may be additionally provided in thebase station 200, if necessary.

FIG. 12 is a diagram illustrating a slot configuration of a TDD-basedmobile communication system according to an embodiment of the presentdisclosure.

Referring to FIG. 12 , a slot may be defined by four configurations of aslot (DL-only) including only DL symbols, a DL symbol-centric slot(DL-centric), a UL symbol-centric slot (UL-centric), and a slot(UL-only) including only UL symbols.

One slot may include 7 symbols. A gap (GP) may exist when changing froma downlink to an uplink or from an uplink to a downlink. That is, a gapmay be inserted between a downlink and an uplink or between an uplinkand a downlink. One symbol may be used to transmit downlink controlinformation. Hereinafter, a symbol that configures a gap is referred toas a gap symbol.

A slot (DL-only) including only DL symbols literally includes only DLsymbols. For example, a slot including only DL symbols includes 7 DLsymbols as in DL-only of FIG. 12 .

A DL symbol-centric slot (DL-centric) includes multiple DL symbols, atleast one gap symbol, and at least one UL symbol. For example, a DLsymbol-centric slot may sequentially include 5 DL symbols, 1 gap symbol,and 1 UL symbol as in DL-centric of FIG. 12 .

A UL symbol-centric slot (UL-centric) may include at least one DLsymbol, at least one gap symbol, and multiple UL symbols. For example, aUL symbol-centric slot may sequentially include 1 DL symbol, 1 gapsymbol, and 5 UL symbols as in UL-centric of FIG. 12 .

A slot (UL-only) including only UL symbols literally includes only ULsymbols. For example, a slot including only UL symbols includes 7 ULsymbols as in UL-only of FIG. 12 .

A network may inform a terminal of a default slot configuration, and tothis end, RRC signaling may be used. Information on the default slotconfiguration configured via RRC signaling may be referred to assemi-static DL/UL assignment information. The default slot configurationis a slot configuration that the terminal may assume that the networkuses, when a base station does not transmit signaling for a separateslot configuration change to the terminal. A 3GPP NR system supportsdynamic TDD that changes the slot configuration according to varioustraffic situations of terminals. To this end, the base station mayinform the terminal of the slot configuration of current or future slotsevery slot, every several slots, or each time the base station changesthe slot configuration. In order to inform about the slot configuration,two methods may be used in the NR system.

A first method is a method of using group common PDCCH. Group commonPDCCH is PDCCH broadcast to multiple terminals, and may be transmittedevery slot, every several slots, or only when a base station is needed.Group common PDCCH may include a (dynamic) slot format informationindicator (SFI) to transmit information relating to a slotconfiguration, and the slot format information indicator may informabout the current slot configuration, in which group common PDCCH istransmitted, or multiple future slot configurations including thecurrent slot configuration. When group common PDCCH is received, theterminal may know the current slot configuration or the future slotconfiguration including the current slot via the slot configurationinformation indicator included in group common PDCCH. If reception ofgroup common PDCCH fails, the terminal cannot determine whether the basestation has transmitted group common PDCCH.

A second method is a method of transmitting information on a slotconfiguration in terminal-specific (UE-specific) PDCCH for scheduling ofPDSCH or PUSCH. UE-specific PDCCH may be transmitted in unicast only toa specific user requiring scheduling. UE-specific PDCCH may transmit, asslot configuration information of a scheduled slot, the same slot formatinformation indicator as that transmitted in group common PDCCH.Alternatively, UE-specific PDCCH may include information that allows aconfiguration of the scheduled slot to be inferred. For example, theterminal may know a slot, to which PDSCH or PUSCH is allocated, and aposition of an OFDM symbol within the slot, by receiving UE-specificPDCCH allocated to the terminal itself, and may infer the configurationof the slot therefrom. UE-specific PDCCH for scheduling of PDSCH mayindicate a slot, in which PUCCH including HARQ-ACK feedback informationis transmitted, and a position of an OFDM symbol in the slot, and aconfiguration of the slot in which PUCCH is transmitted may be inferredtherefrom.

Hereinafter, a downlink signal used in the present specification is aradio signal transmitted from a base station to a terminal and mayinclude a physical downlink channel generated and processed in aphysical layer, a sequence, reference signals (DM-RS, CSI-RS, TRS,PT-RS, etc.), and a MAC message and an RRC message (or RRC signaling)generated and processed in a MAC layer and an RRC layer respectively.The MAC message and the RRC message may be referred to as higher layersignaling as being distinguished from a signal of the physical layerconstituting a lower layer of OSI. Here, the physical downlink channelmay further include a physical downlink shared channel (PDSCH), aphysical downlink control channel (PDCCH), and a physical broadcastchannel (PBCH).

An uplink signal used in the present specification is a radio signaltransmitted by a terminal to a base station, and may include a physicaluplink channel generated and processed in a physical layer, a sequence,reference signals (SRS, etc.), and a MAC message and an RRC message (orRRC signaling) generated and processed in a MAC layer and an RRC layer,respectively. The physical uplink channel may again include an physicaluplink shared channel (PUSCH), an physical uplink uplink control channel(PUCCH), and a physical random access channel (PRACH).

FIG. 13 is a diagram illustrating a physical uplink control channel(PUCCH) used in a wireless communication system according to anembodiment of the present disclosure.

Referring to FIG. 13 , the 3GPP NR system may use two types of PUCCHaccording to a size (i.e., the number of symbols) of a time resourceused for PUCCH transmission.

First type PUCCH may be referred to as long PUCCH and may be transmittedby being mapped to four or more consecutive symbols of a slot. The firsttype PUCCH may be mainly used to transmit a large amount of uplinkcontrol information (UCI) or may be allocated to users with a low signalstrength, so as to enable an increase in coverage of PUCCH. The firsttype PUCCH may be repeatedly transmitted in multiple slots to increasethe coverage of PUCCH. The first type PUCCH may include PUCCH format 1which transmits UCI of a 1 or 2 bit size, PUCCH format 3 which does notsupport multiplexing between users while transmitting UCI exceeding 2bits, and PUCCH format 4 which supports multiplexing between users whiletransmitting UCI exceeding 2 bits.

Second type PUCCH may be referred to as short PUCCH, may be transmittedby being mapped to one or two symbols of a slot, may be used to transmita small amount of UCI or allocated to users with a high signal strength,and may also be used to support a service requiring low latency. Secondtype PUCCH may include PUCCH format 0 for transmission of 1 or 2 bit UCIand PUCCH format 2 for transmission of UCI exceeding 2 bits.

In one slot, there may be a time-frequency resource available for thefirst type PUCCH and a time-frequency resource available for the secondtype PUCCH, which may be allocated to different terminals respectively,or to one terminal. When allocated to one terminal, the first type PUCCHand the second type PUCCH may be transmitted in different time resources(i.e., different OFDM symbols). That is, when allocated to one terminal,the first type PUCCH and the second type PUCCH may be time divisionmultiplexed (TDM) so as to be transmitted.

UCI mapped to PUCCH may include a scheduling grant (SR), HARQ-ACK, rankinformation (RI), CSI, and beam-related information (BRI). The SR isinformation that informs a base station that there is uplinktransmission. The HARQ-ACK is information that informs whether receptionof a physical downlink shared channel (PDSCH) transmitted by a basestation is successful. The RI is information that informs about a ranktransmittable through a radio channel when multiple antennas are used.The CSI is information that the terminal informs about a value ofmeasuring a channel situation between the base station and the terminal.The BRI is information that provides information on beamforming of atransmitter and a receiver.

Referring to FIG. 13(a), a DL symbol centric (DL-centric) slot may beconfigured and indicated by five DL symbols, one flexible symbol, andone UL symbol. Second type PUCCH having symbol length 1 may be allocatedto the DL symbol centric slot. The second type PUCCH may be located in alast symbol of the slot.

Referring to FIG. 13(b), an illustrated UL symbol centric (UL-centric)slot may be configured and indicated by one DL symbol, one flexiblesymbol, and five UL symbols. First type PUCCH and/or second type PUCCHmay be allocated to the UL symbol centric slot. The first type PUCCH maybe mapped to four symbols and the second type PUCCH may be mapped to alast symbol of the slot.

Referring to FIG. 13(c), first type PUCCH and/or second type PUCCH maybe allocated to a slot in which only UL symbols exist (UL only). Forexample, the first type PUCCH may be mapped to six symbols and thesecond type PUCCH may be mapped to last one symbol of the slot.

Referring to FIG. 12 and FIG. 13 , a slot configuration in which secondtype PUCCH transmission is possible is a DL symbol centric slot, a ULsymbol centric slot, and a slot including only UL symbols, and a slotconfiguration in which first type PUCCH transmission is possible is a ULsymbol centric slot and a slot including only UL symbols. The first typePUCCH and the second type PUCCH are TDMed, and transmittable slots are aUL symbol centric slot and a slot including only UL symbols. Forreference, there is one symbol assigned to uplink in the DL symbolcentric slot, and therefore the second type PUCCH is transmittable butthe first type PUCCH is not transmittable. Accordingly, PDCCH forscheduling of PUCCH may allocate the first type PUCCH to a UL symbolcentric slot or a slot including only UL symbols. PDCCH for schedulingof PUCCH may allocate the second type PUCCH to a DL symbol centric slot,a UL symbol centric slot, or a slot including only UL symbols.

As described above, a base station (or network) may change a slotconfiguration according to traffic and various situations of a terminal,and may inform the terminal of a change in the corresponding slotconfiguration. The slot configuration may be changed as described above,and thus the terminal should receive information on the slotconfiguration or a slot configuration information indicator bymonitoring group common PDCCH and UE-specific PDCCH. However, due toproblems, such as interference and radio channel situations between thebase station and the terminal, the terminal may fail to receive groupcommon PDCCH and UE-specific PDCCH.

If the terminal fails to receive group common PDCCH and/or UE-specificPDCCH, the terminal may not recognize whether the base station haschanged the slot configuration or not. However, in a case where the basestation has changed the slot configuration and PUCCH transmissionscheduled by the terminal is not suitable for the changed slotconfiguration, if the terminal enforces PUCCH transmission as scheduled,PUCCH transmission may fail and this may cause a problem, such astemporary loss of communication or delay. Therefore, in this case, aclear procedure or a preliminary protocol between the terminal and thebase station is required, wherein the procedure or protocol relates towhether the terminal transmits or drops indicated PUCCH, and how toperform transmission if the terminal transmits PUCCH.

Hereinafter, an operation method of the terminal and the base stationwill be described, wherein the operation method is to solve a case wherethe terminal fails to receive group common PDCCH and/or UE-specificPDCCH including a slot configuration information indicator and slotconfiguration-related information.

Provided are definitions of a terminal and an operation method thereof,and a base station and an operation method thereof, wherein, althoughthe terminal has succeeded in receiving UE-specific PDCCH and/or groupcommon PDCCH including a slot configuration information indicator andslot configuration-related information, if a configuration of a slot towhich PUCCH has been allocated (or PUCCH transmission has beenscheduled) is changed and the allocated PUCCH is thus unable to betransmitted, the terminal processes transmission of PUCCH, and the basestation processes reception of the allocated PUCCH.

First Embodiment

The first embodiment relates to a method of implementing a predictablecommunication situation between a terminal and a base station, byplacing certain restrictions on a change in a slot configuration of thebase station. In this case, PUCCH transmission of the terminal may beperformed regardless of a success or failure of reception of groupcommon PDCCH and UE-specific PDCCH.

(Method 1)—Slot Configuration of Slot Including Symbol in Which PUCCH isAllocated (or to be Transmitted) Remains Same Without Change

Method 1 may be applied differently depending on a type of the allocated(or to be transmitted) PUCCH, that is, whether PUCCH is first type PUCCHor second type PUCCH.

i) A slot configuration of a symbol in which the first type PUCCH isallocated (or to be transmitted) remains the same without a change. Thatis, the base station does not change the slot configuration of an OFDMsymbol in which the first type PUCCH is allocated (or to betransmitted), and the terminal also assumes (or agrees or expects) thatthe slot configuration of the OFDM symbol in which the first type PUCCHis allocated (or to be transmitted) is not changed. Accordingly, theterminal may transmit the first type PUCCH regardless of receiving theslot configuration information indicator and the slotconfiguration-related information transmitted in group common PDCCH andUE-specific PDCCH.

ii) A slot configuration of a symbol in which the second type PUCCH isallocated (or to be transmitted) remains the same without a change. Thatis, the base station does not change the slot configuration of thesymbol in which the second type PUCCH is allocated (or to betransmitted), and the terminal also assumes (or agrees or expects) thatthe slot configuration of the symbol in which the second type PUCCH isallocated (or to be transmitted) is not changed. Accordingly, theterminal may transmit second type PUCCH regardless of receiving the slotconfiguration information indicator and the slot configuration-relatedinformation transmitted in group common PDCCH and UE-specific PDCCH.

Method 1 described above has some disadvantages in terms of schedulingflexibility. Therefore, the following describes a method in anotheraspect that allows a slot configuration change of a base station withina certain range.

(Method 2)—Slot Configuration of Symbol in Which PUCCH is Allocated (orto be Transmitted) May be Changed Only within Certain Range

Even if a slot configuration of a symbol in which PUCCH is allocated (orto be transmitted) is changed, the slot configuration may be changedonly to a slot configuration in which PUCCH transmission is possible,and may not be changed to a slot configuration in which PUCCHtransmission is impossible. Therefore, the terminal does not expect achange to a slot in which PUCCH transmission is impossible, with respectto the slot indicated with PUCCH transmission by the base station.Method 2 may be applied differently depending on a type of the allocated(or to be transmitted) PUCCH, that is, whether PUCCH is first type PUCCHor second type PUCCH.

When the base station changes the slot configuration of the symbol towhich the first type PUCCH is allocated, the slot configuration may bechanged to only a slot configuration in which the first type PUCCHtransmission is possible, and may not be changed to a slot configurationin which the first type PUCCH transmission is impossible. Therefore, theterminal does not expect a change to a slot in which the first typePUCCH cannot be transmitted, with respect to the slot indicated with thefirst type PUCCH transmission by the base station. Even if the terminalfails to receive group common PDCCH including the slot configurationinformation indicator of the slot that transmits the first type PUCCH,the terminal may always transmit the first type PUCCH in an assignedresource.

For example, the base station may change a UL symbol centric slot, towhich first type PUCCH of a four OFDM symbol length is allocated, to aslot including only UL symbols, but cannot change the same to a slotincluding only a DL symbol having one UL symbol or a DL symbol centricslot. On the other hand, the terminal may expect that the UL symbolcentric slot, to which the first type PUCCH of a four OFDM symbol lengththat the base station has indicated for transmission is allocated, maybe changed to a slot including only UL symbols but does not expect achange to a slot including only DL symbols or to a DL symbol centricslot. The terminal does not expect a change in the slot configuration inwhich UL symbol(s) indicated by the base station to transmit the firsttype PUCCH is changed to the DL symbol(s).

ii) When the base station changes the slot configuration of the symbolto which the second type PUCCH is allocated, the slot configuration maybe changed to a slot configuration in which the second type PUCCHtransmission is possible, and may not be changed to a slot configurationin which the second type PUCCH transmission is impossible. Therefore,the terminal does not expect a change to a slot in which the second typePUCCH transmission is impossible, with respect to the slot indicatedwith the second type PUCCH transmission by the base station. Even if theterminal fails to receive group common PDCCH including the slotconfiguration information indicator of the slot that transmits thesecond type PUCCH, the terminal may always transmit the second typePUCCH in an assigned resource. More specifically, the base station maychange the UL symbol centric slot, to which the second type PUCCH isallocated, to a DL symbol centric slot in which the second type PUCCHtransmission is possible or a slot including only UL symbols, but cannotchange the same to a slot including only DL symbols, in which the secondtype PUCCH transmission is impossible. The terminal does not expect thebase station to make a change to a slot in which the second type PUCCHcannot be transmitted, with respect to the slot indicated fortransmission of the second type PUCCH.

For example, the terminal may expect (or predict) that a UL symbolcentric slot, to which the second type PUCCH of a one or two symbollength that the base station has indicated for transmission isallocated, may be changed to a DL symbol centric slot in which thesecond type PUCCH may be included or a slot including only UL symbols,but does not expect (or predict) the UL symbol centric slot to bechanged to a slot including only DL symbols, in which the second typePUCCH cannot be included. The terminal does not expect a change in theslot configuration in which the UL symbol(s) indicated by the basestation to transmit the second type PUCCH is changed to the DLsymbol(s).

Hereinafter, another method in another aspect for further increasingscheduling flexibility is described in comparison with aforementionedmethod 2 that allows a slot configuration change of a base station to bewithin a certain range.

(Method 3)—Slot Configuration of Symbol in Which PUCCH is Allocated (orto be Transmitted) May be Freely Changed

The base station may freely change a configuration of a slot to whichPUCCH is allocated.

In a case where PUCCH is first type PUCCH, if the terminal fails toreceive group common PDCCH including the slot configuration informationindicator of the slot for transmission of the first type PUCCH, theterminal may not transmit the first type PUCCH in an assigned resource.

In a case where PUCCH is second type PUCCH, if the terminal fails toreceive group common PDCCH including the slot configuration informationindicator of the slot for transmission of the second type PUCCH, theterminal may not transmit the second type PUCCH in the assignedresource.

When the aforementioned method is applied, even if the terminal fails toreceive group common PDCCH and/or UE-specific PDCCH from the basestation, since determination of transmission or non-transmission and atransmission procedure of scheduled PUCCH are clearly defined,communication errors or delay problems may be solved.

Second Embodiment

The second embodiment relates to an operation procedure of a terminaland a base station when a slot configuration of the base station is freeto change and the terminal succeeds in receiving at least one ofUE-specific PDCCH and group common PDCCH including a slot configurationinformation indicator and slot configuration-related information.

More specifically, the present disclosure relates to a terminal and anoperation method thereof, and a base station and an operation methodthereof, wherein, when a configuration of a slot in which PUCCH isallocated (or PUCCH transmission is scheduled) is changed, and thechanged slot configuration is contradicted to PUCCH (i.e., when a symbolto which PUCCH is allocated in the slot to which the PUCCH is allocatedoverlaps a DL symbol due to the changed slot configuration), theterminal processes transmission of the PUCCH, and the base stationprocesses reception of the PUCCH.

In the changed slot configuration, transmission of the allocated PUCCHmay or may not be possible (or valid, suitable) (if the slotconfiguration is contradicted). Here, a slot in which PUCCH transmissionis possible may include, with reference to FIG. 13 , a UL symbol centricslot or slot including only UL symbols, to which first type PUCCH isallocated, and a DL symbol centric slot, UL symbol centric slot, or slotincluding only UL symbols, to which second type PUCCH is allocated. Aslot in which PUCCH cannot be transmitted may include, for example, acase where the slot to which the first type PUCCH is allocated ischanged to a DL symbol centric slot or a slot configuration includingonly DL symbols, a case where the slot to which the second type PUCCH isallocated is changed to a slot configuration including only DL symbols,or the like.

When the configuration of the slot indicated for transmission of PUCCHis changed, if transmission of PUCCH is possible (or valid, suitable) inthe changed slot configuration, the terminal may perform transmission ofPUCCH by using the changed slot. However, in order to transmit PUCCHeven when the configuration of the indicated slot is changed and thuscontradicts transmission of PUCCH, a special protocol between theterminal and the base station is required.

Hereinafter, in the present specification, a method of processing PUCCHunder a contradicted slot configuration will be described. Since uplinkcontrol information (UCI) may be transmitted to a base station throughPUCCH, PUCCH described herein may be used interchangeably with UCI. Forexample, a method of processing PUCCH in a contradicted slotconfiguration corresponds to a method of processing UCI (HARQ-ACK, RI,etc.) in a contradicted slot configuration.

(Method 1)—Method of Processing PUCCH in Indicated Slot

First, a PUCCH processing method under a contradicted slot configurationwhen allocated PUCCH is the first type PUCCH will be described. UCI(HARQ-ACK, RI, CSI, etc.) described with reference to FIG. 3 is mappedto the first type PUCCH.

In description of PUCCH processing method, the terminal may receivegroup common PDCCH including a slot configuration information indicatorof a slot indicated for transmission of the first type PUCCH, and theterminal may perform transmission of the first type PUCCH or the secondtype PUCCH in the indicated slot. In order for the terminal to transmitthe first type PUCCH or the second type PUCCH in the indicated slot, thefollowing conditions may be considered.

As an example, the terminal may transmit the first type PUCCH in theindicated slot on the basis of a result of comparing a UL symbolaccording to a slot configuration of the slot indicated for transmissionof the first type PUCCH with a UL symbol assigned to transmission of thefirst type PUCCH. If the UL symbol according to the slot configurationin the slot indicated for transmission of the first type PUCCH is largerthan (or greater than or equal to) the UL symbol required fortransmission of the first type PUCCH, the terminal transmits the firsttype PUCCH in an assigned resource in the slot.

As another example, the terminal may transmit first type PUCCH or dropor suspend the transmission on the basis of a result of comparing thenumber of UL symbols according to a slot configuration in a slotindicated for transmission of the first type PUCCH with the number of ULsymbols required for transmission of the first type PUCCH. Specifically,if the number of UL symbols according to the slot configuration in theslot indicated for transmission of the first type PUCCH is less than thenumber of UL symbols required for transmission of the first type PUCCH,the terminal may drop transmission of the first type PUCCH in theindicated slot. For example, if the slot indicated for transmission ofPUCCH corresponds to multiple slots, the terminal may delay transmissionof the first type PUCCH to a second slot that provides a UL symbolrequired for transmission of the first type PUCCH, instead of ascheduled first slot, thereby transmitting the first type PUCCH on thesecond slot. On the other hand, if the slot indicated for transmissionof PUCCH is a single slot, the terminal may drop or suspend thescheduled first type PUCCH transmission.

As another example, the terminal may transmit first type PUCCH on thebasis of a result of comparing the number of UL symbols according to aslot configuration in a slot indicated for transmission of the firsttype PUCCH, the number of flexible symbols, and the number of UL symbolsassigned to transmission of the first type PUCCH. Specifically, if thesum of the number of UL symbols and the number of flexible symbolsaccording to the slot configuration in the slot indicated fortransmission of the first type PUCCH is larger than (or greater than orequal to) the number of UL symbols required for transmission of thefirst type PUCCH, the terminal transmits the first type PUCCH in anassigned resource in the slot.

As another example, the terminal may transmit the first type PUCCH ordrop or suspend the transmission on the basis of a result of comparingthe number of UL symbols according to the slot configuration in the slotindicated for transmission of the first type PUCCH, the number offlexible symbols, and the number of UL symbols assigned for transmittingthe first type PUCCH. Specifically, if the sum of the number of ULsymbols and the number of flexible symbols according to the slotconfiguration in the slot indicated for transmission of the first typePUCCH is less than the number of UL symbols required for transmission ofthe first type PUCCH, the terminal may drop transmission of the firsttype PUCCH in the indicated slot. If the slot indicated for transmissionof PUCCH corresponds to multiple slots, the terminal may transmit thefirst type PUCCH in a slot that satisfies the number of UL symbolsassigned to transmission of the first type PUCCH among the multipleslots. On the other hand, if the slot indicated for transmission ofPUCCH is a single slot, the terminal may drop or suspend the scheduledfirst type PUCCH transmission.

In another example of the method of processing PUCCH, the terminal mayreceive group common PDCCH and UE-specific PDCCH indicating a slotconfiguration of a slot indicated for transmission of first type PUCCH,and may transmit the first type PUCCH or the second type PUCCH accordingto a condition to be described later. In this case, the terminal maydetermine whether to transmit the first type PUCCH in the indicatedslot, based on a condition according to the following examples.

FIG. 14 is a diagram illustrating a method of transmitting PUCCH on aslot according to an embodiment of the present disclosure.

As an example, i) a base station may change a configuration of a slot towhich first type PUCCH is allocated, ii) when a terminal successfullyreceives group common PDCCH and UE-specific PDCCH indicating theconfiguration of the slot to which the first type PUCCH is allocated,iii) if the configuration of the slot corresponds to a slot in which thefirst type PUCCH can be transmitted, the terminal may transmit the firsttype PUCCH in an allocated resource of the slot.

As another example, i) the base station may change the configuration ofthe slot to which the first type PUCCH is allocated, ii) the terminalmay successfully receive group common PDCCH and UE-specific PDCCHindicating the configuration of the slot to which the first type PUCCHis allocated. However, iii) if the configuration of the slot correspondsto a slot in which the first type PUCCH cannot be transmitted, theterminal may not perform transmission of the first type PUCCH in theslot, may transmit the first type PUCCH corresponding to the changedslot configuration, or may transmit (referring to FIG. 14 ) second typePUCCH in the slot instead of the first type PUCCH. The specific PUCCHtransmission operation of the terminal is summarized as follows.

a. The terminal does not perform allocated first type PUCCHtransmission.

b-1. In a case of a slot configuration (or format) having a length(e.g., 4 to 12 symbols) of a symbol that can configure the first typePUCCH, if the number of UL symbols which may configure the first typePUCCH in the corresponding slot is less than the preconfigured number offirst type PUCCH symbols to be transmitted, the terminal transmits thefirst type PUCCH in accordance with UL symbols transmittable in thechanged slot configuration (or format) or corresponding to at least 4symbols in length even if it is less than the number of UL symbols.

b-2. Transmission of UCI intended for the terminal may be configured sothat the terminal transmits the first type PUCCH corresponding to afixed symbol length (i.e. 4 symbol length) regardless of the UL symboltransmittable in the corresponding slot.

c. Although the configuration of the slot enables no first type PUCCH,if the slot is capable of transmitting the second type PUCCH, theterminal may transmit, instead of transmitting the allocated first typePUCCH, the second type PUCCH in the slot. The amount of UCItransmittable through the second type PUCCH in the slot may be limited.In this case, the terminal may transmit the UCI, based on at least oneof the following several methods.

c-1. The terminal may transmit some information according to theimportance of the UCI to be transmitted through the first type PUCCH.For example, the importance or priority of the information transmittablein the first type PUCCH may be defined in the order of HARQ-ACK, rankinformation (RI), channel state information (CSI), beam-relatedinformation (BRI) (e.g., beam recovery request) (i.e.,HARQ-ACK>RI>CSI>BRI). As another example, the importance or priority ofinformation transmittable in the first type PUCCH may be defined in theorder of HARQ-ACK, beam-related information, RI, and CSI (i.e.,HARQ-ACK>BRI>RI>CSI). As another example, the importance or priority ofinformation transmittable in the first type PUCCH may be defined in theorder of beam-related information, HARQ-ACK, RI, and CSI (i.e.,BRI>HARQ-ACK>RI>CSI).

c-2. The terminal may transmit some information of high importancethrough the second type PUCCH according to the amount of UCItransmittable through the second type PUCCH.

c-3. When information to be transmitted in the first type PUCCH includesinformation of a primary cell (PCell) and a secondary cell (SCell), theterminal may transmit some information according to the importance orpriority between the PCell and the SCell. For example, the terminal maytransmit only information related to the PCell through the second typePUCCH. As another example, when information to be transmitted in thefirst type PUCCH includes information of a PCell or a primary secondarycell (PSCell), the terminal may transmit only information related to thePCell or PSCell through the second type PUCCH.

c-4. The terminal may preferentially transmit UCI for DL associated witha PUCCH transmittable cell (e.g., SIB linked DL Cell) on each PUCCHgroup through the second type PUCCH.

c-5. The terminal may transmit the second type PUCCH, based on theimportance between the SCell and the PCell and the importance of theUCI. For example, the terminal may transmit a type of UCI having a highpriority among UCI (HARQ-ACK, BRI, RI, CSI, etc.) related to the PCellthrough the second type PUCCH. In c-5, rather than a type of UCI to betransmitted through the second type PUCCH, a serving cell to which theUCI is related is preferentially considered. Of course, a type of UCI tobe transmitted through the second type PUCCH may be consideredpreferentially over a serving cell to which the UCI is related. Thepriority between the serving cell and the UCI may be, while beingincluded in configuration information such as RRC signaling, transmittedto the terminal by the base station, or may be individually definedaccording to a payload size of the second type PUCCH.

c-6. The terminal may transmit only UCI up to a specific bit through thesecond type PUCCH according to the payload size of the UCI. For example,the terminal may be configured to transmit UCI up to X bits through thesecond type PUCCH, where X may be 2 to several tens of bits.

c-7. The terminal may be configured to transmit HARQ-ACK or BRI up to Xbits through the second type PUCCH on the basis of a specific type ofUCI (i.e., HARQ-ACK or BRI), where X may be 2 to several tens of bits.

As another example, there may be a case where i) the base station maychange the configuration of the slot to which the first type PUCCH isallocated, and ii) the terminal successfully receives group common PDCCHand UE-specific PDCCH indicating the configuration of the slot to whichthe first type PUCCH is allocated. In this case, iii) the configurationof the slot corresponds to a slot in which first type PUCCH may betransmitted, iv) PUSCH is allocated to the slot (or PUSCH transmissionis scheduled), and is configured for concurrent transmission of PUCCHand PUSCH, and v) if the inter-modulation distortion (IMD) may occur dueto frequency separation between PUCCH and PUSCH, and it is thusconfigured to transmit no first type PUCCH, the terminal performs atleast one of the specific operations (a to c-7).

Next, a case where the allocated PUCCH is the second type PUCCH will bedescribed. UCI (HARQ-ACK, RI, CSI, etc.) described in FIG. 3 is mappedto the second type PUCCH.

In description of PUCCH processing method, the terminal may receivegroup common PDCCH including a slot configuration information indicatorof a slot indicated for transmission of the second type PUCCH, and theterminal may perform transmission of the second type PUCCH in theindicated slot. In this case, conditions to be described below may beconsidered for whether the terminal is to perform transmission of thesecond type PUCCH in the indicated slot.

For example, the terminal may transmit second type PUCCH on the basis ofa result of comparing the number of UL symbols according to a slotconfiguration in a slot indicated for transmission of the second typePUCCH with the number of UL symbols assigned to transmission of thesecond type PUCCH. Specifically, if the number of UL symbols accordingto the slot configuration in the slot indicated for transmission of thesecond type PUCCH is larger than (or greater than or equal to) thenumber of UL symbols required for transmission of the second type PUCCH,the terminal transmits the second type PUCCH in an assigned resource inthe slot.

As another example, the terminal may transmit second type PUCCH or dropor suspend the transmission on the basis of a result of comparing thenumber of UL symbols according to a slot configuration in a slotindicated for transmission of the second type PUCCH with the number ofUL symbols required for transmission of the second type PUCCH.Specifically, if the number of UL symbols according to the slotconfiguration in the slot indicated for transmission of the second typePUCCH is less than the number of UL symbols required for transmission ofthe second type PUCCH, the terminal may drop transmission of the secondtype PUCCH in the indicated slot. For example, if the slot indicated fortransmission of PUCCH corresponds to multiple slots, the terminal maytransmit the second type PUCCH in a second slot that satisfies thenumber of UL symbols required for transmission of the second type PUCCHamong the multiple slots. On the other hand, if the slot indicated fortransmission of PUCCH is a single slot, the terminal may drop or suspendthe scheduled second type PUCCH transmission.

As another example, the terminal may transmit second type PUCCH on thebasis of a result of comparing the number of UL symbols according to aslot configuration in a slot indicated for transmission of the secondtype PUCCH, the number of flexible symbols, and the number of UL symbolsassigned to transmission of the second type PUCCH. Specifically, if thesum of the number of UL symbols and the number of symbols includingflexible symbols according to the slot configuration in the slotindicated for transmission of the second type PUCCH is larger than (orgreater than or equal to) the number of UL symbols required fortransmission of the second type PUCCH, the terminal transmits the secondtype PUCCH in an allocated resource in the slot.

As another example, the terminal may transmit the second type PUCCH ordrop or suspend the transmission on the basis of a result of comparingthe number of UL symbols according to the slot configuration in the slotindicated for transmission of the second type PUCCH, the number offlexible symbols, and the number of UL symbols required for transmittingthe second type PUCCH. Specifically, if the sum of the number of ULsymbols and the number of flexible symbols according to the slotconfiguration in the slot indicated for transmission of the second typePUCCH is less than the number of UL symbols required for transmission ofthe second type PUCCH, the terminal may drop transmission of the secondtype PUCCH in the indicated slot. For example, if the slot indicated fortransmission of PUCCH corresponds to multiple slots, the terminal maytransmit the second type PUCCH in a second slot that satisfies thenumber of UL symbols required for transmission of the second type PUCCHamong the multiple slots. On the other hand, if the slot indicated fortransmission of PUCCH is a single slot, the terminal may drop or suspendthe scheduled second type PUCCH transmission.

(Method 2)—Method of Processing PUCCH in Slot Different from IndicatedSlot

In description of PUCCH processing method according to method 2, if theconfiguration of the slot indicated for transmission of PUCCH ischanged, the terminal may perform PUCCH transmission in another slotafter the indicated slot. That is, if a UL symbol carrying the PUCCH ina slot to which PUCCH is allocated overlaps a DL symbol in the slot dueto a changed slot configuration, the terminal may postpone or defertransmission of PUCCH to another slot in which transmission of PUCCH ispossible, instead of the indicated slot.

In the other deferred slot, PUCCH of the same type as the allocatedspecific type of PUCCH may be transmitted, or PUCCH of a type differentfrom the allocated specific type of PUCCH may be transmitted. In theother deferred slot, a resource when PUCCH of the same type as PUCCH ofthe allocated specific type is transmitted may be different from aresource in the time domain for transmission of pre-allocated PUCCH ofthe specific type.

In the present specification, first, a PUCCH processing method under acontradicted slot configuration when allocated PUCCH is first type PUCCHwill be described. First type PUCCH may include the UCI described inFIG. 3 , in particular, HARQ-ACK, RI, CSI, and the like. Sinceinformation mapped to first type PUCCH is UCI, PUCCH described in thepresent specification may be used interchangeably with UCI.

FIG. 15 is a diagram illustrating an example of a configuration in whichPUCCH is transmitted on another slot according to a change in a slotconfiguration.

Referring to FIG. 15(a), a terminal may recognize that UL symbol centricslot N to which first type PUCCH (long PUCCH) is allocated has beenchanged to a DL symbol centric slot configuration in which first typePUCCH cannot be transmitted by a base station, via reception of groupcommon PDCCH and/or UE-specific PDCCH indicating the slot configurationchange. In this case, the terminal may transmit first type PUCCH indeferred slot N+K without transmitting first type PUCCH in slot N. Thatis, in the deferred slot N+K, first type PUCCH having the same type asthe allocated first type PUCCH is transmitted. Here, slot N+K is aclosest slot in which the allocated first type PUCCH is transmittable,and may be a UL symbol centric slot.

That is, even if the base station changes the configuration of the slotto which first type PUCCH is allocated and the terminal succeeds inreceiving group common PDCCH and UE-specific PDCCH including the slotconfiguration information, if the configuration of the slot correspondsto a slot in which first type PUCCH cannot be transmitted, the terminalmay not transmit first type PUCCH in the slot, and may transmit firsttype PUCCH in a closest slot in which first type PUCCH is transmittable,from among subsequent slots.

Referring to FIG. 15(b), the terminal may recognize that UL symbolcentric slot N to which first type PUCCH (long PUCCH) is allocated hasbeen changed to a slot configuration in which first type PUCCH cannot betransmitted by a base station, via reception of group common PDCCHand/or UE-specific PDCCH indicating the slot configuration change. Inthis case, the terminal may transmit second type PUCCH (short PUCCH) inslot N+K without transmitting first type PUCCH in slot N. In thedeferred slot N+K, second type PUCCH having a type different from thatof the allocated first type PUCCH is transmitted. That is, in thedeferred slot N+K, second type PUCCH, which has a type changed from thatof the allocated first type PUCCH, is transmitted. Here, slot N+K is aclosest slot in which the second type PUCCH is transmittable, and may bea DL symbol centric slot.

That is, even if the base station changes the configuration of the slotto which first type PUCCH is allocated and the terminal succeeds inreceiving group common PDCCH and UE-specific PDCCH including the slotconfiguration information, if the configuration of the slot correspondsto a slot in which first type PUCCH cannot be transmitted, the terminalmay not transmit first type PUCCH in the slot, and may transmit thesecond type PUCCH in a closest slot in which the second type PUCCH istransmittable, from among subsequent slots.

Here, UCI transmitted through the second type PUCCH may include only apart of UCI that is originally scheduled for transmission according toits importance, and may not include the remaining part.

The terminal may transmit some information according to the importanceof the UCI to be transmitted through first type PUCCH. For example, theimportance or priority of the information transmittable in first typePUCCH may be defined in the order of HARQ-ACK, rank information (RI),channel state information (CSI), beam-related information (BRI) (e.g.,beam recovery request) (i.e., HARQ-ACK>RI>CSI>BRI). As another example,the importance or priority of information transmittable in first typePUCCH may be defined in the order of HARQ-ACK, beam-related information,RI, and CSI (i.e., HARQ-ACK>BRI>RI>CSI). As another example, theimportance or priority of information transmittable in first type PUCCHmay be defined in the order of beam-related information, HARQ-ACK, RI,and CSI (i.e., BRI>HARQ-ACK>RI>CSI).

The terminal may transmit some information of high importance throughthe second type PUCCH according to the amount of UCI transmittablethrough the second type PUCCH.

When information to be transmitted in first type PUCCH includesinformation of a primary cell (PCell) and a secondary cell (SCell), theterminal may transmit some information according to the importance orpriority between the PCell and the SCell. For example, the terminal maytransmit only information related to the PCell through the second typePUCCH. As another example, when information to be transmitted in firsttype PUCCH includes information of a PCell or a primary secondary cell(PSCell), the terminal may transmit only information related to thePCell or PSCell through the second type PUCCH.

The terminal may preferentially transmit UCI for DL associated with aPUCCH transmittable cell (e.g., SIB linked DL Cell) on each PUCCH groupthrough the second type PUCCH.

The terminal may transmit the second type PUCCH, based on the importancebetween the SCell and the PCell and the importance of the UCI. Forexample, the terminal may transmit a type of UCI having a high priorityin UCIs (HARQ-ACK, beam-related information, RI, CSI, etc.) related tothe primary cell through the second type PUCCH. In c-5, rather than atype of UCI to be transmitted through the second type PUCCH, a servingcell to which the UCI is related is preferentially considered. Ofcourse, a type of UCI to be transmitted through the second type PUCCHmay be considered preferentially over a serving cell to which the UCI isrelated. The priority between the serving cell and the UCI may be, whilebeing included in configuration information such as RRC signaling,transmitted to the terminal by the base station, or may be individuallydefined according to a payload size of the second type PUCCH.

The terminal may transmit only UCI up to a specific bit through thesecond type PUCCH according to the payload size of the UCI. For example,the terminal may be configured to transmit UCI up to X bits through thesecond type PUCCH, where X may be 2 to several tens of bits.

The terminal may be configured to transmit HARQ-ACK or BRI up to X bitsthrough the second type PUCCH on the basis of a specific type of UCI(i.e., HARQ-ACK or BRI), where X may be 2 to several tens of bits.

(Method 3)—Method of Processing HARQ-ACK in Slot Different fromIndicated Slot

In description of the HARQ-ACK processing method, the base station maychange the configuration of slot N to which PUCCH is allocated, and theterminal may receive group common PDCCH and/or UE-specific PDCCHincluding information on the changed slot configuration. If theallocated PUCCH cannot be transmitted under the changed slotconfiguration (i.e., if the changed slot configuration is contradictedto the allocated PUCCH), the terminal may transmit the allocated PUCCHafter deferring HARQ-ACK information from slot N by K slots (i.e., N+K)among the allocated PUCCHs. The “allocated PUCCH” may be first typePUCCH or second type PUCCH. Value K may be determined according to thetime taken by the base station to PUCCH feedback in PDSCH scheduling. NoPUCCH for HARQ-ACK feedback of another terminal may be allocated in aslot, in which PUCCH is transmittable, after slot N+K. For example, whenthe terminal and the base station communicate with each other based onfrequency division duplex (FDD), PUCCH for HARQ-ACK of other terminalsmay not be transmitted (or allocated) (common to 3GPP LTE, LTE-A, andNR) in a slot for transmission after 4 ms. Value K may be provided viaan RRC signal.

In description of another HARQ-ACK processing method, the base stationmay change the configuration of slot N to which first type PUCCH isallocated, and the terminal may receive group common PDCCH and/orUE-specific PDCCH including information on the changed slotconfiguration. If, based on the changed slot configuration, first typePUCCH cannot be transmitted, but the second type PUCCH can betransmitted, the terminal may wait or request for PUCCH reallocation ofthe base station without transmitting first type PUCCH. For example, thebase station may retransmit PDSCH to the terminal that has transmittedno first type PUCCH including the HARQ-ACK of PDSCH and may assign aresource in which first type PUCCH is newly transmitted in PDCCH forscheduling of PDSCH.

In description of another HARQ-ACK processing method, the base stationmay change the configuration of slot N to which PUCCH is allocated, andif the terminal has failed to receive group common PDCCH fortransmission of the configuration information of slot N but has receivedUE-specific PDCCH for scheduling of PDSCH (or PUSCH) so as to know theslot configuration of slot N, the terminal may selectively transmit thePUCCH on the basis of the slot configuration. For example, if the slotconfiguration is a slot configuration in which the allocated PUCCH istransmittable, the terminal may transmit the PUCCH. As another example,if the slot configuration is a slot configuration in which the allocatedPUCCH cannot be transmitted, the terminal may not transmit PUCCH. Here,the allocated PUCCH may be first type PUCCH or second type PUCCH.

Third Embodiment

The third embodiment relates to information on a slot configurationtransmitted to a terminal by a base station, and a method of operating aterminal and a base station on the basis of the information. The basestation may inform the terminal of information on the slot configurationby using a variety of information and procedures.

(Method 1)—Information on Slot Configuration

The information on a slot configuration includes semi-static DL/ULassignment information. For example, the base station may transmit adefault slot format or semi-static DL/UL assignment information (orsemi-static slot-format information (SFI)) to the terminal in acell-specific manner, and may additionally transmit semi-static DL/ULassignment information to the terminal via a UE-specific RRC message.When the semi-static DL/UL assignment information (or default slotformat) is received, the terminal may know slot configurations ofsubsequent slots. Specifically, semi-static DL/UL assignment information(or default slot format) indicates information on whether each symbol inthe slot is a DL symbol, a UL symbol, or a flexible symbol other thanthe DL symbol and the UL symbol. Here, the terminal may assume that asymbol indicated as neither a DL symbol nor a UL symbol is indicated as“flexible”, via semi-static DL/UL assignment information (or defaultslot format).

Information on the slot configuration includes dynamic slot-formatinformation (SFI) included in group common PDCCH so as to betransmitted. The dynamic slot format information indicates informationon whether each symbol in the slot is a DL symbol, a UL symbol, or aflexible symbol other than the DL symbol and the UL symbol. The flexiblesymbol may replace a gap and may be used for different purposes otherthan the gap. Group common PDCCH in which dynamic slot formatinformation is transmitted may be scrambled with SFI-RNTI. Whether theterminal monitors the dynamic slot format information may be configuredor indicated by an RRC message. The terminal not indicated formonitoring by the RRC message may not monitor the dynamic slot formatinformation.

Information on the slot configuration may be scheduling informationincluded in downlink control information (DCI) mapped to UE-specificPDCCH. For example, if information on a start position and a length ofPDSCH is included in DCI, symbols in which the PDSCH is scheduled may beassumed to be DL symbols. If information on a start position and alength of PUSCH is included in DCI, symbols in which the PUSCH isscheduled may be assumed to be UL symbols. If information on a startposition and a length of PUCCH for HARQ-ACK transmission is included inDCI, the symbols in which PUCCH is scheduled may be assumed to be ULsymbols.

(Method 2)—Method of Determining Symbol Direction and Method ofProcessing PUCCH

Since there is a variety of information on a slot configuration asdescribed above, the terminal may receive information on different typesof slot configuration for the same slot. Further, the base station mayallow information on each slot configuration to indicate a differentsymbol direction in the same slot. In this case, a change ordetermination of a symbol direction by the terminal and the base stationmay follow the rules below.

The directions of DL symbols and UL symbols of semi-static DL/ULassignment information (or default slot format) are not changed bydynamic slot configuration information or scheduling information.Therefore, if PUCCH is located in UL symbols configured by semi-staticDL/UL assignment information (or default slot format), the terminal maytransmit PUCCH regardless of dynamic slot configuration information orscheduling information. If at least one of the symbols to which PUCCH isallocated overlaps the DL symbol of the default slot format, theterminal may not transmit the corresponding PUCCH, or may change thelength of PUCCH in accordance with the length of the remaining symbolsexcept for the corresponding DL symbol so as to transmit PUCCH. Here,the allocated PUCCH may be first type PUCCH or second type PUCCH.

The direction of the flexible symbol configured by the semi-static DL/ULassignment information (or default slot format) may be determined orchanged by dynamic slot configuration information or schedulinginformation. If at least one of the symbols to which PUCCH is allocatedoverlaps the flexible symbol of semi-static DL/UL assignment information(or default slot format), the terminal may determine whether to transmitPUCCH according to the type (HARQ-ACK, RI, SR, CSI, etc.) of theinformation (i.e., UCI) transmitted by PUCCH. PUCCH may be first typePUCCH or second type PUCCH. For example, if the information transmittedthrough PUCCH includes the HARQ-ACK for PDSCH, the terminal transmitsPUCCH at a determined position regardless of the dynamic slotconfiguration information indicated by group common PDCCH. Here, thedetermined position is indicated in DCI for scheduling of the PDSCH. Ifthe information transmitted through PUCCH does not include HARQ-ACK forPDSCH, the terminal transmits PUCCH when the flexible symbol overlappingPUCCH is indicated as the UL symbol by the dynamic slot configurationinformation.

If at least one of the symbols to which PUCCH is allocated is indicatedas a different symbol (e.g., DL symbol or flexible symbol) other thanthe UL symbol by dynamic slot configuration information, the terminaldoes not transmit PUCCH. Alternatively, if the terminal fails to receivethe dynamic slot configuration information for the symbol to which PUCCHis allocated, the terminal does not transmit PUCCH.

If at least one of the symbols to which PUCCH is allocated overlaps theflexible symbol configured by semi-static DL/UL assignment, the terminalmay determine whether to transmit PUCCH according to signaling thattriggers transmission of PUCCH. For example, if PUCCH is triggered viaDCI, the terminal transmits PUCCH at a determined position regardless ofthe dynamic slot configuration information. Here, the determinedposition is indicated in the DCI. If PUCCH is triggered through theUE-specific RRC message, the terminal transmits PUCCH when the symbolsto which PUCCH is allocated are indicated as the UL symbol by thedynamic slot configuration information.

If at least one of the symbols to which PUCCH is allocated is indicatedas a different symbol (e.g., DL symbol or flexible symbol) other thanthe UL symbol by dynamic slot configuration information, the terminaldoes not transmit PUCCH. Alternatively, if the terminal fails to receivethe dynamic slot configuration information for the symbol to which PUCCHis allocated, the terminal does not transmit PUCCH.

(Method 3)—Method of Processing Repetition PUCCH

The terminal may repeatedly transmit PUCCH over several slots. In thepresent specification, this PUCCH is described as repetition PUCCH.Repetition PUCCH may be first type PUCCH or second type PUCCH. The basestation may configure the number of slots, in which repetition PUCCH istransmitted, to the terminal via an RRC message. Within each slot, astart symbol and an end symbol of PUCCH may be the same for eachrepeated slot. According to each case where DL symbols, UL symbols, andflexible symbols are configured by RRC, such as semi-static DL/ULassignment information (or default slot pattern), and the dynamic slotconfiguration information, the terminal may or may not transmitrepetition PUCCH. Hereinafter, a method of processing repetition PUCCHin each case will be described.

(Method 3-1)—When Repetition PUCCH Overlaps UL Symbol

If UL symbols configured with semi-static DL/UL assignment information(or default slot pattern) are located in each of slots indicated fortransmission of repetition PUCCH, the terminal may transmit PUCCH in theslot in which the UL symbols are located regardless of reception of thedynamic slot configuration information or the scheduling information.Here, Directions of DL symbols and UL symbols according to the slotconfiguration configured by the RRC message, such as semi-static DL/ULassignment information (or the default slot pattern), are not changed bythe dynamic slot configuration information or the schedulinginformation.

(Method 3-2)—When Repetition PUCCH Overlaps DL Symbol

If at least one of symbols assigned to repetition PUCCH in each slotamong the slots indicated for transmission of repetition PUCCH overlapsthe DL symbol according to the semi-static DL/UL assignment information,the terminal does not transmit PUCCH in a slot including a symboloverlapping the DL symbol or transmits PUCCH by changing the lengththereof in accordance with the length of the remaining symbols exceptfor the overlapping DL symbol. Alternatively, if at least one of thesymbols assigned to repetition PUCCH in one of the slots indicated fortransmission of repetition PUCCH overlaps the DL symbol configured withsemi-static DL/UL assignment information (or default slot pattern), theterminal does not transmit repetition PUCCH in a subsequent slot as wellas in the slot including the overlapping DL symbol.

(Method 3-3)—When Repetition PUCCH Overlaps Flexible Symbol

At least one of symbols to which repetition PUCCH is allocated in eachslot among slots indicated for transmission of repetition PUCCH mayoverlap a flexible symbol configured by semi-static DL/UL assignment. Inthis case, i) the terminal may determine whether to transmit repetitionPUCCH according to the type (HARQ-ACK, RI, CSI, etc.) of information(i.e., UCI) transmitted by repetition PUCCH. ii) The terminal maydetermine whether to transmit repetition PUCCH according to signalingthat triggers PUCCH transmission. iii) The terminal may determinewhether to transmit repetition PUCCH according to the dynamic slotconfiguration information. Repetition PUCCH may be first type PUCCH orsecond type PUCCH.

The terminal may determine whether to transmit repetition PUCCHaccording to the type (HARQ-ACK, RI, CSI, etc.) of information (i.e.,UCI) transmitted by repetition PUCCH. For example, if informationtransmitted through repetition PUCCH includes HARQ-ACK for PDSCHscheduled by PDCCH, the terminal transmits repetition PUCCH at adetermined position regardless of the dynamic slot configurationinformation indicated by group common PDCCH. Here, the determinedposition is indicated in DCI for scheduling of the PDSCH. If theinformation transmitted through repetition PUCCH does not includeHARQ-ACK for PDSCH or includes HARQ-ACK for PDSCH configured via RRC,the terminal transmits repetition PUCCH when the flexible symboloverlapping repetition PUCCH is indicated as the UL symbol by thedynamic slot configuration information. As another example, if at leastone of symbols to which repetition PUCCH is allocated in each slot amongslots indicated for transmission of repetition PUCCH is indicated as adifferent symbol (e.g., DL symbol or flexible symbol) other than a ULsymbol by dynamic slot configuration information, the terminal does nottransmit repetition PUCCH in the slot. Alternatively, if the terminalfails to receive the dynamic slot configuration information for thesymbol to which repetition PUCCH is allocated, the terminal does nottransmit repetition PUCCH in the slot. Even if repetition PUCCH hasfailed to be transmitted in the corresponding slot, if a certaincondition is satisfied in a subsequent slot (when the flexible symboloverlapping repetition PUCCH is indicated as the UL symbol by thedynamic slot configuration information), the terminal transmitsrepetition PUCCH in the subsequent slot.

If the terminal fails to transmit repetition PUCCH in any one of theslots indicated for repetition PUCCH to be transmitted, the terminaldoes not perform repetition transmission of PUCCH even in subsequentslots. An example of not being able to transmit the repetition PUCCH mayinclude contradiction in symbol directions caused by the dynamic slotconfiguration information, a case where the terminal fails to receivethe dynamic slot configuration information, or the like.

If at least one of the symbols to which repetition PUCCH is allocatedoverlaps the flexible symbol configured by semi-static DL/UL assignment,the terminal may determine whether to transmit repetition PUCCHaccording to signaling that triggers transmission of repetition PUCCH.For example, if repetition PUCCH is triggered via DCI, the terminaltransmits repetition PUCCH at a determined position regardless of thedynamic slot configuration information. Here, the determined position isindicated in the DCI. If repetition PUCCH is triggered via a UE-specificRRC message, the terminal transmits repetition PUCCH when the symbols towhich repetition PUCCH is allocated are indicated as the UL symbol bythe dynamic slot configuration information.

In each slot among the slots indicated for transmission of repetitionPUCCH, if at least one of the symbols to which repetition PUCCH isallocated is indicated as a different symbol (e.g., DL symbol orflexible symbol) other than the UL symbol by dynamic slot configurationinformation, the terminal does not transmit repetition PUCCH in theslot. Alternatively, if the terminal fails to receive the dynamic slotconfiguration information for the symbol to which repetition PUCCH isallocated, the terminal does not transmit repetition PUCCH in the slot.Even if repetition PUCCH has failed to be transmitted in thecorresponding slot, if a certain condition is satisfied in a subsequentslot, the terminal transmits repetition PUCCH in the subsequent slot. Anexample of the certain condition may include a case where a flexiblesymbol overlapping repetition PUCCH is indicated as a UL symbol bydynamic slot configuration information.

If the terminal does not transmit repetition PUCCH in the slot for somereason (contradiction in symbol directions caused by the dynamic slotconfiguration information, or the terminal fails to receive the dynamicslot configuration information) in one of the slots indicated fortransmission of repetition PUCCH, the terminal does not performrepetition transmission of PUCCH even in the subsequent slot.

Here, the number K of slots in which PUCCH transmission is repeated (orattempted) may be configured/defined as follows.

i) K slots configured for transmission of repetition PUCCH are notnecessarily consecutive. For example, if the terminal is configured torepeatedly transmit PUCCH during K slots, PUCCH may be repeatedlytransmitted until the count of the number of slots actually transmittedreaches K except for the slot in which repetition PUCCH is nottransmitted.

ii) K slots configured for transmission of repetition PUCCH should beconsecutive. For example, if the terminal is configured to repeatedlytransmit PUCCH during K slots, PUCCH may be repeatedly transmitted fromslot N indicated for transmission of the repetition PUCCH until thecount of the number of slots (including slots in which no repetitionPUCCH is transmitted) having attempted to transmit PUCCH reaches K. Thatis, the terminal having first attempted to transmit PUCCH in slot Nattempts to transmit PUCCH up to slot (N+K−1), and even if the number(or slots) of repetition transmissions of PUCCH actually performed isless than K, the terminal no longer transmits PUCCH in slot (N+K).

The terminal makes an attempt to transmit PUCCH in K consecutive slotsfrom slot N indicated for transmission of repetition PUCCH, wherein theK consecutive slots are among the remaining slots except for slots inwhich PUCCH cannot be transmitted according to semi-static DL/ULassignment information.

FIG. 16 is a diagram illustrating a slot in which repetition PUCCHtransmission is performed according to a slot configuration.

Referring to FIG. 16(a), a description is provided for a case where aterminal transmits first type PUCCH 1500 when the terminal is configured(slot configuration according to semi-static DL/UL assignment) totransmit the first type PUCCH 1500 repeatedly over two slots. Here,flexible symbols may be changed into DL symbols or UL symbols by dynamicslot configuration information or scheduling information of UE-specificDCI. A symbol in which the first type PUCCH 1500 is transmitted isassumed to be symbol 8 to symbol 13 within a slot. 14 symbols areincluded in one slot, and indices of the symbols are from 0 to 13.

Looking at each slot configuration according to the semi-static DL/ULassignment, symbol 0 is a DL symbol and symbol 7-symbol 13 are ULsymbols, in slot 0. In slot 1, symbol 0-symbol 10 are DL symbols, andsymbol 12-symbol 13 are UL symbols. In slot 2, symbol 0-symbol 1 are DLsymbols, and symbol 10-symbol 13 are UL symbols. In slot 3, symbol 0 isa DL symbol, and symbol 7-symbol 13 are UL symbols. The remainingsymbols except for the UL symbols and the DL symbols are flexiblesymbols.

Therefore, the first type PUCCH 1500 can be transmitted in slot 0 andslot 3 regardless of dynamic slot configuration information, and cannotbe transmitted in slot 1 regardless of dynamic slot configurationinformation, and if symbol 8 and symbol 9 are indicated as the ULsymbols by the dynamic slot configuration information in slot 2, thefirst type PUCCH 1500 may be transmitted, but may not be transmittedotherwise.

FIG. 16(a) illustrates a slot in which the terminal attempts to transmitthe first type PUCCH 1500 according to the aforementioned i). In thiscase, since symbols 8 and 9 of slot 2 are not indicated as UL symbols bythe dynamic slot configuration information, it is assumed that theterminal cannot transmit first type PUCCH. The terminal actuallytransmits the first type PUCCH 1500 twice in slot 0 and slot 3.Therefore, the terminal no longer repeatedly transmits the first typePUCCH 1500 after slot 3.

FIG. 16(b) illustrates a slot making an attempt to transmit the firsttype PUCCH 1500 by using the aforementioned ii). Since the first typePUCCH 1500 is configured to be repeatedly transmitted in two slots(K=2), the terminal attempts to transmit the first type PUCCH 1500 inslot 0 and slot 1. The terminal attempts to transmit first type PUCCH inslot 1, but cannot transmit first type PUCCH due to an overlap with theDL symbol according to the configuration of semi-static DL/UL assignmentinformation.

FIG. 16(c) illustrates a slot attempting to transmit the first typePUCCH 1500 by using the aforementioned repetition iii). The first typePUCCH 1500 is configured to be repeatedly transmitted in two slots(K=2), but slot 1 is a slot in which first type PUCCH 1500 cannot betransmitted due to semi-static DL/UL assignment information. Therefore,the terminal attempts to transmit first type PUCCH 1500 in slots 0 and2. Slot 2 may or may not actually transmit first type PUCCH 1500 asindicated by the dynamic slot configuration information.

Fourth Embodiment

The fourth embodiment relates to a method of transmitting a physicalchannel by a terminal or a base station to improve physical channelcoverage in a wireless communication system based on a slotconfiguration including a TDD-based DL symbol, a flexible symbol, and aUL symbol and a determination procedure relating thereto. The physicalchannel transmitted by the terminal is a physical uplink channel andincludes PRACH, PUCCH, PUSCH, SRS, and the like. The physical channeltransmitted by the base station is a physical downlink channel andincludes PDSCH, PDCCH, PBCH, and the like. Hereinafter, in the presentspecification, procedures for a terminal and a base station forrepetition transmission of PUCCH are defined, procedures for a terminaland a base station for repetition transmission of PUSCH are defined, andprocedures of a terminal and a base station for a method of repetitiontransmission of PDSCH are defined. PUCCH or repetition PUCCH describedbelow may be first type PUCCH or second type PUCCH.

(Method 1)—Resource Determination Procedures of Terminal and BaseStation, for Repetition Transmission of PUCCH

The number of slots in which PUCCH is transmitted or the number ofrepetitions of PUCCH transmission may be one of predetermined values(e.g., 1, 2, 4, and 8), and a value actually configured to the terminalamong the values is transmitted by an RRC message. If the number ofrepetitions of PUCCH transmission is configured to 1, this indicatesgeneral PUCCH transmission rather than repeatedly transmitted PUCCH.

A starting point and a length of a symbol in a slot in which PUCCH istransmitted are included in information related to one PUCCH resourceconfigured by the base station. Information related to the PUCCHresource may be configured by an RRC parameter. A PUCCH resource setincluding at least one PUCCH resource may be configured or assigned tothe terminal by RRC signaling. The base station may indicate, to theterminal, at least one PUCCH resource index in the PUCCH resource setvia dynamic signaling (i.e., DCI). For example, the base station mayindicate the PUCCH resource index to the terminal, based on a PUCCHresource indicator (PRI) included in DCI or a combination of PRI andimplicit mapping. PRI may have a size of 2 bits or 3 bits.

In this way, the configured PUCCH resource set or PUCCH resource indexmay be maintained the same over multiple slots in which PUCCH isrepeatedly transmitted. The terminal determines whether to transmitPUCCH indicated by DCI, and the determination is made based onsemi-static DL/UL assignment information. The semi-static DL/ULassignment information may include at least one of UL-DL configurationcommon information (TDD-UL-DL-ConfigurationCommon) that may be indicatedvia RRC signaling, and UL-DL configuration dedicated information(TDD-UL-DL-ConfigDedicated) that may be additionally indicated to theterminal via RRC signaling.

For example, i) the UL-DL configuration common information may indicatea period in which semi-static DL/UL assignment information is applied,and may indicate the number of DL symbols, the number of UL symbols, andthe number of flexible symbols configured over multiple slots includedin the period. ii) the UL-DL configuration dedicated information mayinclude information for overriding a flexible symbol in a semi-staticDL/UL slot configuration provided by the UL-DL configuration commoninformation with a UL symbol, a DL symbol, and a flexible symbol. Thatis, the terminal may override the flexible symbol in the slot formatprovided by the UL-DL configuration common information with another typeof symbol on the basis of the UL-DL configuration dedicated information.

If a symbol in which PUCCH is to be transmitted overlaps the symbol(s)indicated by semi-static UL/DL assignment information (at least one ofUL-DL configuration common information and UL-DL configuration dedicatedinformation) in each slot indicated by the base station for PUCCHtransmission, the terminal determines whether to transmit the PUCCH,based on the direction of the indicated symbol(s). For example, if thesymbol(s) in the slot indicated by the base station are DL symbols, theterminal defers transmission of PUCCH to a subsequent slot, and if oneof the indicated symbol(s) is a UL symbol(s) and a flexible symbol(s),the terminal transmits PUCCH in the corresponding slot. As anotherexample, if a symbol in the slot indicated by the base station is a DLsymbol or a flexible symbol(s), the terminal defers transmission ofPUCCH to a subsequent slot, and if the indicated symbol is a UL symbol,the terminal transmits PUCCH in the corresponding slot. PUCCH that isnot transmitted in the corresponding slot may be deferred to thesubsequent slot.

The terminal repeatedly transmits PUCCH on multiple slots until thenumber of repetitions of PUCCH transmission, which isindicated/configured by the RRC message, is reached. The terminal maydetermine a slot for transmission of PUCCH on the multiple slots, basedon a UL symbol and an unknown (or flexible) symbol according toinformation transmitted via an RRC message. For example, the terminalmay determine a slot including a start position of a symbol for PUCCHtransmission and the number of UL symbols, as a slot resource forperforming PUCCH transmission. The slot includes a UL symbol and aflexible symbol configured by the RRC message. The base station mayreceive PUCCH repeatedly transmitted by the terminal via multiple slots,based on at least one of UL-DL configuration common information andUL-DL configuration dedicated information.

If at least one of symbols in which PUCCH is transmitted in a first slotof the slots to which repetition PUCCH transmission is assigned overlapsa DL symbol, the terminal cancels PUCCH transmission withouttransmitting PUCCH in the corresponding slot. That is, if the symbols inwhich PUCCH is transmitted in the first slot of the slots in whichrepetition PUCCH transmission is assigned are configured by UL symbol(s)and a flexible symbol, the terminal may transmit PUCCH in thecorresponding slot. If at least one of the symbols in which PUCCH istransmitted, after PUCCH transmission in a slot subsequent to the firstslot of the slots to which repetition PUCCH transmission is assigned,overlaps a DL symbol or a flexible symbol, the terminal cancels PUCCHtransmission without transmitting PUCCH in the slot. That is, if theslot, in which PUCCH transmission is indicated by the base station inthe slot subsequent to the first slot of the slots to which repetitionPUCCH transmission is assigned, and the symbols of the slot areconfigured by the UL symbol(s), that is, symbols indicated fortransmission of PUCCH, the terminal may transmit PUCCH in thecorresponding slot.

Hereinafter, a PUCCH processing method related to a gap symbol isdescribed.

There may be a gap for DL-UL switching between a DL symbol and an ULsymbol. A gap may be located in a flexible symbol. That is, somesymbol(s) of the flexible symbol(s) between the DL symbol and the ULsymbol may be used for the DL-UL switching gap and may not be used forDL reception or UL transmission. If the number of symbols for the gap isdenoted as G, G may be fixed to a specific value such as 1 or 2, may beset/configured to the terminal by an RRC message, and may be obtainedvia a timing advance (TA) value.

If the symbol in which PUCCH is to be transmitted overlaps the symbol(s)configured by semi-static UL/DL assignment information (at least one ofUL-DL configuration common information and UL-DL configuration dedicatedinformation) in each slot indicated by the base station for PUCCHtransmission, the terminal determines whether to transmit the PUCCH,based on a type (or direction) of the indicated symbol(s). For example,if the indicated symbol(s) are all UL symbols, the terminal transmitsPUCCH, and if at least one of the indicated symbol(s) includes a DLsymbol or one of G consecutive flexible symbol(s) immediately subsequentto the DL symbol, the terminal does not transmit PUCCH in thecorresponding slot. The terminal may defer, to a subsequent slot, PUCCHthat is not transmitted in the corresponding slot. In other words, inthe slot indicated by the base station for PUCCH transmission, if thesymbol in which PUCCH is to be transmitted is a UL symbol, the terminaltransmits PUCCH, and if the symbol in which PUCCH is to be transmittedoverlaps a DL symbol or at least one of G consecutive flexible symbol(s)immediately subsequent to the DL symbol, the terminal does not transmitPUCCH in the slot. The terminal may defer, to a subsequent slot, PUCCHthat is not transmitted in the corresponding slot. That is, PUCCH is nottransmitted if overlapped with any one of G symbols that can be used asa gap with a DL symbol, and transmission is deferred to a subsequentslot.

In relation to the PUCCH processing method in multiple slots, theterminal repeatedly transmits PUCCH until the number of repetitions ofPUCCH transmission set/configured by the RRC message is reached on themultiple slots. The terminal may determine a slot for PUCCH transmissionon the multiple slots, based on the type and number of symbols accordingto information transmitted via the RRC message.

The terminal determines a slot for PUCCH transmission, based on thenumber of UL symbols, the number of flexible symbols, and the number ofgap symbols set/configured by semi-static UL/DL assignment information.For example, if “the number of UL symbols+the number of flexiblesymbols−the number of gap symbols” in a slot includes a transmissionstart symbol position of PUCCH and the number of UL symbols in whichPUCCH is to be transmitted, the terminal may determine the correspondingslot as a slot for PUCCH transmission and may transmit PUCCH.Alternatively, when considering that one slot includes 14 symbols, if“14−(the number of DL symbols in slot+the number of gap symbols)”includes a transmission start symbol position of PUCCH and the number ofUL symbols in which PUCCH is to be transmitted, the terminal maydetermine the corresponding slot as a slot for PUCCH transmission andmay transmit PUCCH.

In this case, the base station may receive PUCCH repeatedly transmittedby the terminal via multiple slots, based on at least one of UL-DLconfiguration common information and UL-DL configuration dedicatedinformation.

FIG. 17 illustrates whether PUCCH is transmitted according to a slotconfiguration.

Referring to FIG. 17 , a slot configuration configured according tosemi-static DL/UL assignment information includes five DL symbols(denoted as “D”), three flexible symbols (denoted as “X”), and six ULsymbols (denoted as “U”) in sequence.

For PUCCH allocation #0, an 8th symbol to a 14th symbol are configuredas resources for PUCCH transmission, and for PUCCH allocation #1, a 7thsymbol to the 14th symbol are configured as resources for PUCCHtransmission, and for PUCCH allocation #3, a 6th symbol to the 14thsymbol are configured as resources for PUCCH transmission.

FIG. 17(a) illustrates a case where a gap corresponds to one symbol(G=1). If G=1, PUCCH allocation #0 and PUCCH allocation #1 which do notinclude one flexible symbol immediately subsequent to DL symbols aretransmittable, but PUCCH allocation #2 including one flexible symbolimmediately subsequent to DL symbols cannot be transmitted. In thiscase, transmission of PUCCH allocation #2 may be deferred to asubsequent slot. Of course, the terminal also determines, based on thesame criteria, whether to transmit PUCCH allocation #2 in the subsequentslot.

FIG. 17(b) illustrates a case where a gap corresponds to two symbols(G=2). If G=2, PUCCH allocation #0 which does not include twoconsecutive or flexible symbols immediately subsequent to DL symbols aretransmittable, but PUCCH allocation #1 and PUCCH allocation #2 whichinclude two consecutive flexible symbols immediately subsequent to DLsymbols cannot be transmitted. In this case, transmission of PUCCHallocations #1 and #2 may be deferred to a subsequent slot. Of course,the terminal also determines, based on the same criteria, whether totransmit PUCCH allocations #1 and #2 in the subsequent slot.

(Method 2)—Resource Determination Procedures of Terminal and BaseStation, for Repetition Transmission of PUSCH

The number of slots in which PUSCH is transmitted or the number ofrepetitions of PUCCH transmission may be, for example, one ofpredetermined values (e.g., 1, 2, 4, and 8), and a value actuallyconfigured to the terminal among the values is transmitted by an RRCmessage. If the number of repetitions of PUSCH transmission isconfigured to 1, this indicates general PUSCH rather than repeatedlytransmitted PUSCH.

In a case of PUSCH transmission, PUSCH transmission is performed only ina slot configuration suitable for PUSCH transmission from among Kconsecutive slots, and a postponing operation of PUSCH transmission isnot performed.

A start symbol and a length (transmission duration) of PUSCHtransmission in a slot are indicated by DCI, and may be maintained thesame in all slots. The terminal determines whether to transmit PUSCHindicated by DCI, and whether to transmit PUSCH may be determined basedon semi-static DL/UL assignment information. The semi-static DL/ULassignment information used for determining whether to transmit PUSCHmay include at least one of UL-DL configuration common information(TDD-UL-DL-ConfigurationCommon) that may be indicated via RRC signaling,and UL-DL configuration dedicated information(TDD-UL-DL-ConfigDedicated) that may be additionally indicated to theterminal via RRC signaling. For example, the UL-DL configuration commoninformation may indicate a period to apply semi-static DL/UL assignmentinformation. The UL-DL configuration common information may be used toconfigure the number of UL/DL symbols per slot, which is configured overmultiple slots included in the period, a slot format configured by thenumber of UL/DL symbols per slot and the number of flexible symbols perslot, and the number of slots. That is, the terminal may configure aslot format for each slot by using the number of slots indicated by theUL-DL configuration common information. As another example, the UL-DLconfiguration dedicated information may include information foroverriding a flexible symbol in a semi-static DL/UL slot configurationprovided by the UL-DL configuration common information with a UL symbol,a DL symbol, and a flexible symbol. That is, the terminal may overridethe flexible symbol in the slot format provided by the UL-DLconfiguration common information with another type of symbol on thebasis of the UL-DL configuration dedicated information.

If the symbol in which PUSCH is to be transmitted overlaps the symbol(s)indicated by semi-static UL/DL assignment information (at least one ofUL-DL configuration common information and UL-DL configuration dedicatedinformation) in each slot indicated by the base station for PUSCHtransmission, the terminal determines whether to transmit the PUSCH,based on a type (or direction) of the indicated symbol(s). For example,if at least one of the indicated symbol(s) is a DL symbol, the terminaldoes not perform PUSCH transmission and cancels PUSCH transmission. Ifthe indicated symbol(s) are UL symbol(s) and flexible symbol(s), theterminal transmits PUSCH in the corresponding slot. As another example,if at least one of the indicated symbol(s) is a DL symbol or a flexiblesymbol(s), the terminal does not perform PUSCH transmission and cancelsPUSCH transmission. If the indicated symbol(s) are UL symbols, theterminal transmits PUSCH in the corresponding slot.

If at least one of the symbols for PUSCH transmission in a first slot ofthe slots indicated for repetition PUSCH transmission overlaps a DLsymbol, the terminal does not transmit PUSCH in the corresponding slotand cancels PUSCH transmission. That is, if symbols for PUSCHtransmission in the first slot of the slots indicated for repetitionPUSCH transmission are configured by a UL symbol(s) and a flexiblesymbol, the terminal may transmit PUSCH in the corresponding slot. If atleast one of the symbols for PUSCH transmission in a slot subsequent tothe first slot of the slots indicated for repetition PUSCH transmissionoverlaps a DL symbol or a flexible symbol, the terminal does nottransmit PUSCH in the corresponding slot and cancels PUSCH transmission.That is, if the symbols configured/indicated for PUSCH transmission in aslot subsequent to the first slot of the slots indicated for repetitionPUSCH transmission are configured by UL symbol(s), the terminal maytransmit PUSCH in the corresponding slot.

Hereinafter, a PUSCH processing method related to a gap symbol isdescribed.

There may be a gap for DL-UL switching between a DL symbol and an ULsymbol. A gap may be located in a flexible symbol. Some symbol(s) of theflexible symbol(s) between the DL symbol and the UL symbol may be usedfor a DL-UL switching gap and may not be used for DL reception or ULtransmission. If the number of symbols for the gap is denoted as G, Gmay be fixed to a specific value such as 1 or 2, may be configured tothe terminal by an RRC message, and may be obtained via a timing advance(TA) value.

If the symbol in which PUSCH is to be transmitted overlaps the symbol(s)indicated by semi-static UL/DL assignment information (at least one ofUL-DL configuration common information and UL-DL configuration dedicatedinformation) in each slot indicated by the base station for PUSCHtransmission, the terminal may determine whether to transmit the PUSCH,based on the type (or direction) of the indicated symbol. For example,if all the indicated symbols are UL symbols, the terminal transmitsPUSCH, and if at least one of the indicated symbols is a DL symbol or Gconsecutive flexible symbol(s) immediately subsequent to the DL symbol,the terminal does not transmit PUSCH in the corresponding slot. That is,in each slot indicated by the base station for PUSCH transmission, ifthe symbol in which PUSCH is to be transmitted is a UL symbol, theterminal transmits PUSCH, and if at least one of the symbols in whichPUSCH is to be transmitted overlaps a DL symbol or at least one of Gconsecutive flexible symbol(s) immediately subsequent to the DL symbol,the terminal does not transmit PUSCH and cancels PUSCH transmission.That is, PUSCH is not transmitted if overlapped with any one of Gsymbols that can be used as a gap with a DL symbol, and transmission ofPUSCH is cancelled.

(Method 3)—Resource Determination Procedures of Terminal and BaseStation, for Repetition Reception of PDSCH

The number of slots in which PDSCH is received or the number ofrepetitions of PDSCH reception may be, for example, one of predeterminedvalues (e.g., 1, 2, 4, and 8), and a value actually configured to theterminal among the values is transmitted by an RRC message. If thenumber of repetitions of PDSCH reception is configured to 1, thisindicates general PDSCH rather than repeatedly transmitted PDSCH.

A start symbol and a symbol duration (length) of symbols in which PDSCHis received in a slot are indicated by DCI, and may be maintained thesame in all slots. The terminal determines whether to receive PDSCHindicated by DCI. This determination may be based on semi-static DL/ULassignment information. The semi-static DL/UL assignment informationused for the determination may include at least one of UL-DLconfiguration common information (TDD-UL-DL-ConfigurationCommon) thatmay be indicated via RRC signaling, and UL-DL configuration dedicatedinformation (TDD-UL-DL-ConfigDedicated) that may be additionallyindicated to the terminal via RRC signaling. For example, the UL-DLconfiguration common information may indicate a period to applysemi-static UL/DL assignment information. The UL-DL configuration commoninformation may be used to configure the number of UL/DL symbols perslot, which is configured over multiple slots included in the period, aslot format configured by the number of UL/DL symbols per slot and thenumber of flexible symbols per slot, and the number of slots. That is,the terminal may configure a slot format for each slot by using thenumber of slots indicated by the UL-DL configuration common information.As another example, the UL-DL configuration dedicated information mayinclude information for overriding a flexible symbol in a semi-staticDL/UL slot configuration provided by the UL-DL configuration commoninformation with a UL symbol, a DL symbol, and a flexible symbol. Thatis, the terminal may override the flexible symbol in the slotconfiguration provided by the UL-DL configuration common informationwith another type of symbol on the basis of the UL-DL configurationdedicated information.

If a symbol in which the terminal is to receive PDSCH overlaps thesymbol(s) indicated by semi-static UL/DL assignment information (atleast one of UL-DL configuration common information and UL-DLconfiguration dedicated information) in a slot indicated by the basestation for PDSCH reception, the terminal may determine whether toreceive the PDSCH, based on the type (or direction) of the indicatedsymbol. For example, if at least one of the indicated symbol(s) is a ULsymbol, the terminal does not perform PDSCH reception. On the otherhand, if the indicated symbol(s) are DL symbol(s) and flexiblesymbol(s), the terminal may receive PDSCH in the corresponding slot. Asanother example, if at least one of the indicated symbol(s) is a ULsymbol or unknown (or flexible symbol(s)), the terminal does not performPDSCH reception. If the indicated symbol(s) are DL symbols, the terminalreceives PDSCH in the corresponding slot.

If at least one of the symbols for PDSCH reception in a first slot ofthe slots indicated for repetition PDSCH reception overlaps a UL symbol,the terminal does not receive PDSCH in the corresponding slot. That is,if symbols for PDSCH reception in the first slot of the slots indicatedfor repetition PDSCH reception are configured by a DL symbol(s) and aflexible symbol, the terminal may receive PDSCH in the correspondingslot. If at least one of the symbols for PDSCH reception in a slotsubsequent to the first slot of the slots indicated for repetition PDSCHreception overlaps a UL symbol or a flexible symbol, the terminal doesnot receive PUSCH in the corresponding slot. That is, if the slotindicated by the base station for PDSCH reception in the slot subsequentto the first slot of the slots indicated for repetition PDSCH reception,and the symbols of the slot are configured by the DL symbol(s), that is,symbols indicated for reception of PDSCH, the terminal may receive PDSCHin the corresponding slot. The terminal may receive, in a deferredsubsequent slot, PDSCH that has failed to be additionally received.

Hereinafter, a PDSCH processing method related to a gap symbol isdescribed.

There may be a gap for DL-UL switching between a DL symbol and an ULsymbol. A gap may be located in a flexible symbol. Some symbol(s) of theflexible symbol(s) between the DL symbol and the UL symbol may be usedfor a DL-UL switching gap and may not be used for DL reception or ULtransmission. If the number of symbols for the gap is denoted as G, Gmay be fixed to a specific value such as 1 or 2, may be configured tothe terminal by an RRC message, and may be obtained via a timing advance(TA) value.

If the symbol in which PDSCH is to be received overlaps the symbol(s)indicated by semi-static UL/DL assignment information (at least one ofUL-DL configuration common information and UL-DL configuration dedicatedinformation) in a slot indicated by the base station for PDSCHreception, the terminal determines whether to receive the PDSCH, basedon the type (or direction) of the indicated symbol. For example, if theindicated symbol(s) are all DL symbols, the terminal receives PDSCH, andif at least one of the indicated symbol(s) is a UL symbol or Gconsecutive flexible symbol(s) immediately preceding the UL symbol, theterminal does not receive PDSCH.

That is, in the slot indicated by the base station for PDSCH reception,if the symbol in which PDSCH is to be received is a DL symbol, theterminal receives PDSCH, and if the symbol in which PDSCH is to bereceived overlaps a UL symbol or at least one of G consecutive flexiblesymbol(s) immediately preceding the UL symbol, the terminal does notperform PDSCH reception. That is, if the symbol in which PDSCH is to betransmitted overlaps any one of G symbols that can be used as a gap withthe UL symbol, the base station does not transmit PDSCH and cancelstransmission of PDSCH. Then, the base station defers transmission ofPDSCH to a subsequent slot.

If the terminal cancels reception of PDSCH according to the semi-staticDL/UL assignment information, since HARQ-ARQ timing may be changed, anew HARQ-ARQ timing configuration method needs to be defined.

If reception of PDSCH is canceled, new HARQ-ARQ timing may be determinedaccording to received PDSCH without being canceled. That is, in order todetermine a slot in which actual HARQ-ACK is transmitted, the terminalmay use last received PDSCH except for HARQ-ACK timing and canceledPDSCH included in DCI indicating PDSCH reception. For example, theterminal indicated with 4 slots as HARQ-ACK timing may transmit HARQ-ACKafter 4 slots from the slot in which last PDSCH is received.

Even if reception of PDSCH is canceled, HARQ-ARQ timing is not changedand may be determined by assuming that PDSCH is received. That is, inorder to determine the slot in which actual HARQ-ACK is transmitted, theterminal may perform calculation based on last PDSCH beforedetermination on cancellation and HARQ-ACK timing included in DCIindicating PDSCH reception. For example, the terminal indicated with 4slots as HARQ-ACK timing may transmit HARQ-ACK after 4 slots from lastslot of allocated PDSCH, even if reception of PDSCH is cancelled.

The terminal may be configured to perform inter-slot frequency hoppingfor frequency diversity. Therefore, even when the terminal repeatedlytransmits PUCCH (or PDSCH, or PUSCH) via multiple slots, it is requiredto define a method for performing inter-slot frequency hopping by theterminal. Hereinafter, the present specification provides descriptionsof a physical resource block (PRB) via which PUCCH (or PDSCH or PUSCH)is to be transmitted in each slot during inter-slot frequency hopping.The present specification also provides descriptions of an algorithm fordetermining a PRB according to a difference between a slot in whichPUCCH is first transmitted and a current slot regardless of the numberof repetition PUCCH transmissions.

The inter-slot frequency hopping method during PUCCH transmission mayinclude determining, by the terminal, a resource block (RB) fortransmission of PUCCH according to an index of a first slot and an indexof a second slot in which repetition PUCCH is first transmitted. In thiscase, the first slot is a slot indicated by the base station for PUCCHtransmission, and the second slot is a slot in which PUCCH istransmitted after the first slot during repetition PUCCH transmission.Here, an RB in which PUCCH is transmitted in slot n_(s) or start RBindices of RBs may be obtained by Equation 1 below.

$\begin{matrix}{{{RB}\left( n_{s} \right)} = \left\{ \begin{matrix}{{{{RB}_{1}\left( {n_{s} - n_{s,0}} \right)}{mod}2} = 0} \\{{{{RB}_{2}\left( {n_{s} - n_{s,0}} \right)}{mod}2} = 1}\end{matrix} \right.} & \left\lbrack {{Equation}1} \right\rbrack\end{matrix}$

In Equation 1, RB₁ and RB₂ are start RB indices of a first hop and asecond hop, respectively, and are signaled to the terminal via an RRCmessage so as to be set/configured for the terminal. n_(s,0) is an indexof a slot in which PUCCH is first transmitted. In this scheme, accordingto deferral of repetition PUCCH, transmission may be performed throughonly one hop while PUCCH is being repeatedly transmitted.

The inter-slot frequency hopping method during PUCCH transmission mayinclude performing hopping every time when the terminal actuallytransmits repetition PUCCH. The RB may be determined by a slot index viawhich PUCCH is to be transmitted and the number of actual repetitions.More specifically, an RB in which PUCCH is transmitted in slot n_(s) orstart RB indices of RBs may be obtained by Equation 2.

$\begin{matrix}{{{RB}\left( n_{s} \right)} = \left\{ \begin{matrix}{RB}_{1} & {{{n^{repeat}\left( n_{s} \right)}{mod}2} = 0} \\{RB}_{2} & {{{n^{repeat}\left( n_{s} \right)}{mod}2} = 1}\end{matrix} \right.} & \left\lbrack {{Equation}2} \right\rbrack\end{matrix}$

In Equation 2, RB₁ and RB₂ are start RB indices of a first hop and asecond hop, respectively, and are signaled to the terminal via an RRCmessage so as to be set/configured for the terminal. n_(repeat) (n_(s))is the number of repetition transmissions of PUCCH before slot n_(s). Inthis scheme, PUCCH may be transmitted through two different hopsregardless of deferral of repetition PUCCH.

Fifth Embodiment

The fifth embodiment describes a method of determining a slot, via whichrepetition PUCCH transmission is to be performed, from among multipleslots, in addition to a method and a determination procedure ofrepeatedly transmitting PUCCH over multiple slots in order to improvecoverage of PUCCH. Specifically, a method of determining, by a terminal,a slot for PUCCH transmission among multiple slots is described.

The terminal may determine a slot for PUCCH transmission, based on anSS/PBCH block including a synchronization signal for radio resourcemanagement (RRM) measurement and information on initial cell access. TheSS/PBCH block may be transmitted at a determined location, and aconfiguration on transmission of the SS/PBCH block may be transmitted tothe terminal from the base station via an RRC message (e.g.,SSB_transmitted-SIB1 information or SSB_transmitted) so as to beset/configured for the terminal. In the slot indicated by theconfiguration on the transmission of the SS/PBCH block, flexible symbolsin which transmission of the SS/PBCH block is possible may exist. Thatis, the flexible symbol may be used not only for PUCCH transmission butalso for transmission of an SS/PBCH block including information onsynchronization and initial cell access. In this case, there may be acase where at least one of the flexible symbol(s), in which PUCCHtransmission is possible, and the flexible symbol(s) for transmission ofthe SS/PBCH block overlap. For example, the terminal may determine aslot for repetition PUCCH in a manner excluding a slot including theoverlapping symbol from the slots for repetition PUCCH transmission,thereby preventing a collision. As such, the terminal may determinemultiple slots for transmission of PUCCH on the basis ofSSB_transmitted-SIB1 and SSB_transmitted, and if PUCCH is repeatedlytransmitted over the multiple slots, the base station may receive therepetition PUCCH from the terminal.

The terminal may determine a slot for PUCCH transmission, based onsemi-static DL/UL assignment information and a gap.

In the present specification, it is assumed that a gap is located in asymbol immediately preceding symbols for PUCCH transmission, and the gapincludes one or two symbols. However, the number of symbols and aposition of a DL-UL switching gap between DLs and ULs may be variouslyconfigured according to configurations of the base station and theterminal, in addition to the description above. For example, a gap mayinclude two or more symbols, and the terminal may determine a slot forPUCCH transmission or may determine whether to defer PUCCH transmission,in consideration of two or more gap symbols.

A slot may be determined based on at least one of whether to allocatePDSCH in a slot, whether to assign a control resource set (CORESET) forPDCCH monitoring to a DL symbol in a slot, whether to assign a CSI-RS ina slot, whether to assign an SS/PBCH block in a slot, and semi-staticDL/UL assignment information. For example, if the symbol immediatelypreceding the flexible symbol is DL symbol(s) and PDSCH is allocated tothe DL symbol(s), the terminal does not consider the flexible symbol asa resource for PUCCH transmission. Instead, the terminal may determine aslot including other UL symbols and flexible symbol(s), as a slot forPUCCH transmission. If the symbol immediately preceding the flexiblesymbol is DL symbol(s) and no PDSCH is allocated to the DL symbol(s),the flexible symbol is an unassigned symbol. Therefore, the terminaldoes not recognize the unassigned symbol as a gap for DL-UL switching.Then, the terminal may consider a flexible symbol immediately subsequentto the DL symbol(s) as a resource capable of repetition PUCCHtransmission and make a determination as a slot for PUCCH transmission.As another example, if a symbol immediately preceding the flexiblesymbol is a DL symbol(s) and CORESET or search space for PDCCHmonitoring is assigned to the DL symbol(s), the terminal may exclude theslot including the flexible symbol from the slots for repetition PUCCHtransmission in order to monitor allocated PDCCH. As another example, ifa symbol immediately preceding the flexible symbol is a DL symbol(s) andCORESET or search space for PDCCH monitoring is assigned to the DLsymbol(s), the terminal may not monitor allocated PDCCH and may considerthe flexible symbol as a resource capable of repetition PUCCHtransmission and make a determination as a slot for PUCCH transmission.

As another example, the terminal may determine a slot for PUCCHtransmission by using semi-static DL/UL assignment information. Theterminal may recognize a slot and a symbol for performing PUCCHtransmission via an RRC message and dynamic signaling (e.g., PRI). If atleast one of the symbols indicated for PUCCH transmission overlaps theflexible symbols indicated in the semi-static DL/UL assignmentinformation, and if the symbol immediately preceding the symbolsindicated for PUCCH transmission is not the DL symbol indicated in thesemi-static DL/UL assignment information, the terminal may determine acorresponding slot as a slot for repetition PUCCH transmission so as totransmit PUCCH in the corresponding slot. If the symbol immediatelypreceding the symbols indicated for PUCCH transmission is the DL symbolindicated in the semi-static DL/UL assignment information, the terminalmay not transmit repetition PUCCH in the corresponding slot and maydefer the PUCCH transmission to a subsequent available slot. In otherwords, if the terminal is able to recognize symbols for transmission ofPUCCH in each slot via an RRC message and/or dynamic signaling (e.g.,PRI), and even at least one of the symbols overlaps the DL symbol of thesemi-static DL/UL assignment information, or, if the symbol immediatelypreceding the symbols in which PUCCH is to be transmitted is the DLsymbol of the semi-static DL/UL assignment information, the terminaldoes not transmit PUCCH in the corresponding slot, and, otherwise, theterminal transmits PUCCH in the corresponding slot. This is because aswitching gap between DL and UL may be needed. PUCCH that has failed tobe transmitted may be deferred so as to be transmitted in a subsequentavailable slot.

As another example, the terminal may determine a slot for PUCCHtransmission by using information scheduled from the base station. Theterminal may recognize a slot and a symbol for PUCCH transmission via anRRC message and dynamic signaling (e.g., PRI). If at least one of thesymbols indicated for PUCCH transmission overlaps the flexible symbolsindicated in the semi-static DL/UL assignment information, and PDSCH isnot scheduled in a symbol immediately preceding the symbols indicatedfor PUCCH transmission, the terminal may determine the correspondingslot as a slot for PUCCH transmission so as to transmit PUCCH in thecorresponding slot. If PDSCH is scheduled in the symbol immediatelypreceding the symbols indicated for PUCCH transmission, the terminal maydefer PUCCH transmission to a subsequent available slot withouttransmitting PUCCH in the corresponding slot. In other words, theterminal may recognize symbols in which PUCCH is to be transmitted inevery slot, via an RRC message and/or dynamic signaling (e.g., PRI). Ifeven at least one of the recognized symbols overlaps the DL symbol ofthe semi-static DL/UL assignment information, or PDSCH is scheduled inthe symbol immediately preceding the symbols indicated for PUCCHtransmission, the terminal may not transmit PUCCH in the correspondingslot and, otherwise, the terminal may transmit PUCCH in thecorresponding slot. This is because a switching gap between DL and ULmay be needed. PUCCH that has failed to be transmitted may be deferredso as to be transmitted in a subsequent available slot.

As another example, the terminal may determine a slot for PUCCHtransmission by using CSI-RS information set/configured from the basestation. The terminal may recognize in which symbol of which slot PUCCHshould be transmitted, via an RRC message and dynamic signaling (e.g.,PRI). If at least one of the symbols indicated for PUCCH transmissionoverlaps the flexible symbols indicated in the semi-static DL/ULassignment information, and CSI-RS reception is not configured in asymbol immediately preceding the symbols indicated for PUCCHtransmission, the terminal may determine the corresponding slot as aslot for PUCCH transmission so as to transmit PUCCH in the correspondingslot. If CSI-RS reception is configured in the symbol immediatelypreceding the symbols indicated for PUCCH transmission, the terminal maydefer PUCCH transmission to a subsequent available slot withouttransmitting PUCCH in the corresponding slot. In other words, theterminal may recognize symbols in which PUCCH is to be transmitted inevery slot, via an RRC message and/or dynamic signaling (e.g., PRI). Ifeven at least one of the recognized symbols overlaps the DL symbol ofthe semi-static DL/UL assignment information, or CSI-RS reception isconfigured in a symbol immediately preceding the symbols indicated forPUCCH transmission, the terminal may not transmit PUCCH in thecorresponding slot and, otherwise, the terminal may transmit PUCCH inthe corresponding slot. This is because a switching gap between DL andUL may be needed. PUCCH that has failed to be transmitted may bedeferred so as to be transmitted in a subsequent available slot.

As another example, the terminal may determine a slot for PUCCHtransmission by using PDCCH monitoring information configured to theterminal. The terminal may recognize in which symbol of which slot PUCCHshould be transmitted, via an RRC message and dynamic signaling (e.g.,PRI). If at least one of symbols indicated for PUCCH transmissionoverlaps flexible symbols in semi-static DL/UL assignment information,and PDCCH monitoring is not configured (or assigned) in a symbolimmediately preceding the symbols indicated for PUCCH transmission, theterminal may determine the corresponding slot as a slot for PUCCHtransmission so as to transmit PUCCH in the corresponding slot. If PDCCHmonitoring is configured (or assigned) in the symbol immediatelypreceding the symbols indicated for PUCCH transmission, the terminal maydefer PUCCH transmission to a subsequent available slot withouttransmitting PUCCH in the corresponding slot. In other words, if theterminal is able to recognize symbols, in which PUCCH is to betransmitted, in each slot from an RRC message and/or dynamic signaling(e.g., PRI), and even at least one of the symbols overlaps a DL symbolof the semi-static DL/UL assignment information, or, if PDCCH monitoringis configured in the symbol immediately preceding the symbols indicatedfor PUCCH transmission, the terminal may not transmit PUCCH in thecorresponding slot and, otherwise, the terminal may transmit PUCCH inthe corresponding slot. This is because a switching gap between DL andUL may be needed. PUCCH that has failed to be transmitted may bedeferred so as to be transmitted in a subsequent available slot.

As another example, the terminal may recognize a slot and a symbol inwhich PUCCH should be transmitted, via an RRC message and dynamicsignaling (e.g., PRI). There may be a case where at least one of thesymbols indicated for PUCCH transmission overlaps flexible symbolsindicated in semi-static DL/UL assignment information, and a symbolimmediately preceding the symbols indicated for PUCCH transmission doesnot overlap an SS/PBCH block. In this case, the terminal may determinethe corresponding slot as a slot for PUCCH transmission so as totransmit PUCCH in the corresponding slot. If the symbol immediatelypreceding the symbols indicated for PUCCH transmission overlaps theSS/PBCH block, the terminal may defer PUCCH transmission to a subsequentavailable slot without transmitting PUCCH in the corresponding slot. Inother words, the terminal may recognize symbols in which PUCCH is to betransmitted in every slot, from an RRC message and/or dynamic signaling(e.g., PRI). If even at least one of the symbols overlaps a DL symbol ofsemi-static DL/UL assignment information, or the symbol immediatelypreceding the symbols indicated for PUCCH transmission overlaps theSS/PBCH block, the terminal may not transmit PUCCH in the correspondingslot and, otherwise, the terminal may transmit PUCCH in thecorresponding slot. This is because a switching gap between DL and ULmay be needed. PUCCH that has failed to be transmitted may be deferredso as to be transmitted in a subsequent available slot.

In the present specification, when describing whether to perform PUCCHtransmission and deferral, descriptions are provided mainly based on atleast one symbol in consideration of a symbol immediately precedingsymbols for PUCCH transmission. However, a switching gap between DL andUL may be configured/applied variously according to configurations of abase station and a terminal, and therefore the number of gap symbols isnot limited to one symbol and may be, of course, configured/applied tovarious symbols.

There may be a case where a symbol indicated as a DL symbol by dynamicsignaling (e.g., SFI) in one slot ends at a symbol immediately precedinga symbol for repetition PUCCH transmission, and a PUCCH resource isconfigured so that transmission for repetition PUCCH is performed from asubsequent symbol. The terminal may not transmit PUCCH in the slot anddefer transmission to a subsequent slot, and the deferred slot may be anearliest slot among slots in which the PUCCH is transmittable.

A method of determining a slot for PUCCH transmission according towhether the terminal allocates PDSCH in a slot will be described with amore specific example. Here, it is assumed that one slot includes 14symbols.

For example, it is assumed that a UL symbol resource for PUCCH isconfigured with last 12 symbols of a slot, and a specific slotsequentially includes 2 DL symbols, 2 flexible symbols, and 10 ULsymbols. If PDSCH is allocated to 2 DL symbols immediately preceding 2flexible symbols, the terminal implicitly considers a first flexiblesymbol as a switching gap between DL and UL. The terminal determineswhether 1 flexible symbol and 10 UL symbols remaining after excludingthe first flexible symbol are configurable as a resource for PUCCHtransmission. However, since the UL symbol resource for PUCCH isconfigured with last 12 symbols of the slot, the terminal may excludethe slot from the slot resource for PUCCH transmission (it is because ULsymbols (including flexible symbols) available for PUCCH transmissionare last 11 symbols). In the above example, if the UL symbol resourcefor PUCCH is configured with last 11 symbols of the slot, the terminalmay determine the slot as the slot resource for PUCCH transmission.

As another example, it is assumed that a UL symbol resource for PUCCH isconfigured with last 6 symbols of a slot, and a specific slotsequentially includes 8 DL symbols, 2 flexible symbols, and 4 ULsymbols. If PDSCH is allocated to the preceding 8 DL symbols, theterminal implicitly considers a first flexible symbol as a switching gapbetween DL and UL. The terminal determines whether 1 flexible symbol and4 UL symbols remaining after excluding the first flexible symbol areconfigurable as a PUCCH resource. However, since the UL symbol resourcefor PUCCH is configured with last 6 symbols of the slot, the terminalmay exclude the slot from the slot resource for PUCCH transmission (itis because UL symbols (including flexible symbols) available for PUCCHtransmission are last 5 symbols). In the above example, if the UL symbolresource for PUCCH is configured with last 5 symbols of the slot, theterminal may determine the slot as the slot resource for PUCCHtransmission.

Sixth Embodiment

The sixth embodiment relates to a method of determining a slot, viawhich repetition PUSCH transmission is to be performed, from amongmultiple slots, in addition to a method and a determination procedure ofrepeatedly transmitting PUSCH over multiple slots in order to improvecoverage of PUSCH.

A slot in which PUSCH is to be transmitted may be determined based on atleast one of whether to allocate PDSCH in a slot, whether to assign acontrol resource set (CORESET) for PDCCH monitoring to a DL symbol in aslot, whether to assign a CSI-RS in a slot, whether to assign an SS/PBCHblock in a slot, and semi-static DL/UL assignment information. Forexample, the terminal may determine a slot for PUSCH transmission byusing semi-static DL/UL assignment information. The terminal mayrecognize a slot and a symbol in which PUSCH is transmitted, via an RRCmessage and dynamic signaling (e.g., PRI). If symbols indicated forPUSCH transmission overlap flexible symbols indicated in semi-staticDL/UL assignment information, and if a symbol immediately preceding thesymbols indicated for PUSCH transmission is not a DL symbol indicated inthe semi-static DL/UL assignment information, the terminal may determinethe corresponding slot as a slot for PUSCH transmission so as totransmit PUSCH in the corresponding slot. If the symbol immediatelypreceding the symbols indicated for PUSCH transmission is the DL symbolindicated in the semi-static DL/UL assignment information, the terminalmay not transmit PUSCH in the corresponding slot and may defer PUSCHtransmission to a subsequent available slot. In other words, theterminal may recognize symbols in which PUSCH is to be transmitted inevery slot, from an RRC message and/or dynamic signaling (e.g., PRI). Ifeven at least one of the recognized symbols overlaps the DL symbol ofthe semi-static DL/UL assignment information, or a symbol immediatelypreceding symbols in which PUSCH is to be transmitted is the DL symbolof the semi-static DL/UL assignment information, the terminal may nottransmit PUSCH in the corresponding slot and, otherwise, the terminalmay transmit PUSCH in the corresponding slot. This is because aswitching gap between DL and UL may be needed. PUSCH that has failed tobe transmitted may be deferred so as to be transmitted in a subsequentavailable slot.

As another example, the terminal may determine a slot for PUSCHtransmission by using information scheduled to the terminal. Theterminal may recognize a slot and a symbol in which PUSCH should betransmitted, via an RRC message and dynamic signaling (e.g., PRI). If atleast one of the symbols indicated for PUSCH transmission overlaps theflexible symbols indicated in the semi-static DL/UL assignmentinformation, and PDSCH is not scheduled in a symbol immediatelypreceding the symbols indicated for PUSCH transmission, the terminal maydetermine the corresponding slot as a slot for PUSCH transmission so asto transmit PUSCH in the corresponding slot. If PDSCH is scheduled inthe symbol immediately preceding the symbols indicated for PUSCHtransmission, the terminal may defer PUSCH transmission to a subsequentavailable slot without transmitting PUSCH in the corresponding slot. Inother words, the terminal may recognize symbols in which PUSCH is to betransmitted in every slot, from an RRC message and/or dynamic signaling(e.g., PRI). If even at least one of the recognized symbols overlaps theDL symbol of the semi-static DL/UL assignment information, or PDSCH isscheduled in the symbol immediately preceding the symbols in which PUSCHis to be transmitted, the terminal does not transmit PUSCH in thecorresponding slot and, otherwise, the terminal transmits PUSCH in thecorresponding slot. This is because a switching gap between DL and ULmay be needed. PUSCH that has failed to be transmitted may be deferredso as to be transmitted in a subsequent available slot.

As another example, the terminal may determine a slot for PUSCHtransmission by using CSI-RS information set/configured from the basestation. The terminal may know in which symbol of which slot PUSCHshould be transmitted, via an RRC message and dynamic signaling (e.g.,PRI). If at least one of the symbols indicated for PUSCH transmissionoverlaps flexible symbols indicated in the semi-static DL/UL assignmentinformation, and CSI-RS reception is not configured in a symbolimmediately preceding the symbols indicated for PUSCH transmission, theterminal may determine the corresponding slot as a slot for PUSCHtransmission so as to transmit PUSCH in the corresponding slot. IfCSI-RS reception is configured in the symbol immediately preceding thesymbols indicated for PUSCH transmission, the terminal does not transmitPUSCH in the corresponding slot. In other words, the terminal mayrecognize symbols in which PUSCH is to be transmitted in every slot,from an RRC message and/or dynamic signaling (e.g., PRI). If even atleast one of the recognized symbols overlaps the DL symbol of thesemi-static DL/UL assignment information, or CSI-RS reception isconfigured in a symbol immediately preceding the symbols indicated forPUSCH transmission, the terminal may not transmit PUSCH in thecorresponding slot and, otherwise, the terminal may transmit PUSCH inthe corresponding slot. This is because a switching gap between DL andUL may be needed. PUSCH that has failed to be transmitted may bedeferred so as to be transmitted in a subsequent available slot.

As another example, the terminal may determine a slot for PUSCHtransmission by using PDCCH monitoring information set/configured fromthe base station. The terminal may recognize a slot and a symbol inwhich PUSCH should be transmitted, via an RRC message and dynamicsignaling (e.g., PRI). If at least one of symbols indicated for PUSCHtransmission overlaps flexible symbols indicated in semi-static DL/ULassignment information, and PDCCH monitoring is not configured (orassigned) in a symbol immediately preceding the symbols indicated forPUSCH transmission, the terminal may determine the corresponding slot asa slot for PUSCH transmission so as to transmit PUSCH in thecorresponding slot. If PDCCH monitoring is configured (or assigned) inthe symbol immediately preceding the symbols indicated for PUSCHtransmission, the terminal may not transmit PUSCH in the correspondingslot. In other words, the terminal may recognize symbols in which PUSCHis to be transmitted in every slot, via an RRC message and/or dynamicsignaling (e.g., PRI). If even at least one of the recognized symbolsoverlaps the DL symbol of the semi-static DL/UL assignment information,or PDCCH monitoring is configured in a symbol immediately preceding thesymbols in which PUSCH is to be transmitted, the terminal does nottransmit PUSCH in the corresponding slot and, otherwise, the terminaltransmits PUSCH in the corresponding slot. This is because a switchinggap between DL and UL may be needed. PUSCH that has failed to betransmitted may be deferred so as to be transmitted in a subsequentavailable slot.

As another example, the terminal may recognize a slot and a symbol inwhich PUSCH should be transmitted, via an RRC message and dynamicsignaling (e.g., PRI). If at least one of the symbols indicated forPUSCH transmission overlaps flexible symbols indicated in semi-staticDL/UL assignment information, and a symbol immediately preceding thesymbols indicated for PUSCH transmission does not overlap an SS/PBCHblock, the terminal may determine the corresponding slot as a slot forPUSCH transmission so as to transmit PUCCH in the corresponding slot. Ifthe symbol immediately preceding the symbols indicated for PUSCHtransmission overlaps the SS/PBCH block, the terminal does not transmitPUSCH in the corresponding slot. In other words, the terminal may knowsymbols in which PUSCH is to be transmitted in every slot, via an RRCmessage and/or dynamic signaling (e.g., PRI). If even at least one ofthe recognized symbols overlaps a DL symbol of the semi-static DL/ULassignment information, or the symbol immediately preceding the symbolsin which PUSCH is to be transmitted overlaps the SS/PBCH block, theterminal does not transmit PUSCH in the corresponding slot and,otherwise, the terminal transmits PUSCH in the corresponding slot. Thisis because a switching gap between DL and UL may be needed. PUSCH thathas failed to be transmitted may be deferred so as to be transmitted ina subsequent available slot.

In the present disclosure, when describing PUSCH transmission anddeferral, descriptions are provided mainly based on an example of atleast one symbol in consideration of a symbol immediately precedingsymbols for PUSCH transmission. However, a DL-UL switching gap may beconfigured variously according to configurations of a base station and aterminal, and therefore whether to perform PUSCH transmission anddeferral may be, of course, determined in consideration of one or moresymbols.

Seventh Embodiment

The seventh embodiment relates to a method of determining a slot, viawhich repetition PDSCH transmission is to be performed, from amongmultiple slots, in addition to a method and a determination procedure ofrepeatedly transmitting PDSCH over multiple slots in order to improvecoverage of PDSCH.

A slot in which PDSCH is to be received may be determined based on atleast one of whether to allocate PUSCH in a slot, whether to allocatePUCCH, whether to assign SRS transmission, whether to assign PRACHtransmission, and semi-static DL/UL assignment information.

For example, the terminal may determine a slot in which PDSCH is to bereceived, by using semi-static DL/UL assignment information. Theterminal may recognize a slot and a symbol in which PDSCH should bereceived, via an RRC message and dynamic signaling (e.g., PRI). If atleast one of the symbols indicated for PDSCH reception overlaps flexiblesymbols indicated in semi-static DL/UL assignment information, and asymbol immediately subsequent to the symbols indicated for PDSCHreception is not a UL symbol indicated in the semi-static DL/ULassignment information, the terminal may determine the correspondingslot as a slot for PDSCH reception so as to receive PDSCH in thecorresponding slot. If the symbol immediately subsequent to the symbolsindicated for PDSCH reception is a UL symbol indicated in thesemi-static DL/UL assignment information, the terminal does not receivePDSCH in the corresponding slot. In other words, the terminal mayrecognize symbols in which PDSCH is to be transmitted in every slot,from an RRC message and/or dynamic signaling (e.g., PRI). If even atleast one of the recognized symbols overlaps the UL symbol of thesemi-static DL/UL assignment information, or a symbol immediatelysubsequent to symbols in which PDSCH is to be transmitted is the ULsymbol of the semi-static DL/UL assignment information, the terminaldoes not receive PDSCH in the corresponding slot and, otherwise, theterminal receives PDSCH in the corresponding slot.

As another example, the terminal may determine a slot for PDSCHreception by using uplink information (PUSCH, PUCCH, PRACH, SRS, etc.)scheduled from the base station. The terminal may recognize a slot and asymbol in which PDSCH should be received, via an RRC message and dynamicsignaling (e.g., PRI). If at least one of symbols indicated for PDSCHreception overlaps flexible symbols indicated in semi-static DL/ULassignment information, and PUSCH, PUCCH, PRACH, or SRS is not scheduledin a symbol immediately subsequent to the symbols indicated for PDSCHreception, the terminal may determine the corresponding slot as a slotfor PDSCH reception so as to receive PDSCH in the corresponding slot. IfPUSCH, PUCCH, PRACH, or SRS is scheduled in the symbol immediatelysubsequent to the symbols indicated for PDSCH reception, the terminaldoes not receive PDSCH in the corresponding slot. In other words, theterminal may recognize symbols in which PDSCH is to be received in everyslot, via an RRC message and/or dynamic signaling (e.g., PRI). If evenat least one of the recognized symbols overlaps the UL symbol of thesemi-static DL/UL assignment information, or PUSCH, PUCCH, PRACH, or SRSis scheduled in the symbol immediately subsequent to the symbols inwhich PDSCH is to be transmitted, the terminal does not receive PDSCH inthe corresponding slot and, otherwise, the terminal receives PDSCH inthe corresponding slot. Here, PUCCH may be for transmission of HARQ-ACK.Alternatively, PUCCH may be for transmission of a scheduling request(SR).

As another example, the terminal may determine a slot for PDSCHtransmission by using CSI-RS information set/configured from the basestation. The terminal may recognize a slot and a symbol in which PDSCHshould be transmitted, via an RRC message and dynamic signaling (e.g.,PRI). If at least one of the symbols indicated for PDSCH receptionoverlaps flexible symbols indicated in semi-static DL/UL assignmentinformation, and CSI-RS reception is not configured in a symbolimmediately preceding the symbols indicated for PDSCH reception, theterminal may determine the corresponding slot as a slot for PDSCHtransmission so as to transmit PDSCH in the corresponding slot. IfCSI-RS reception is configured in the symbol immediately preceding thesymbols indicated for PDSCH reception, the terminal may defer PDSCHtransmission to a subsequent available slot without transmitting PDSCHin the corresponding slot. In other words, the terminal may recognizesymbols in which PDSCH is to be transmitted in every slot, via an RRCmessage and/or dynamic signaling (e.g., PRI). If even at least one ofthe recognized symbols overlaps the DL symbol of the semi-static DL/ULassignment information, or CSI-RS reception is configured in a symbolimmediately preceding symbols in which PDSCH is to be transmitted, theterminal does not transmit PDSCH in the corresponding slot and,otherwise, the terminal transmits PDSCH in the corresponding slot. Thisis because a switching gap between DL and UL may be needed. PDSCH thathas failed to be transmitted may be deferred so as to be transmitted ina subsequent available slot.

As another example, the terminal may determine a slot for PDSCHtransmission by using PDCCH monitoring information set/configured fromthe base station. The terminal may recognize a slot and a symbol inwhich PDSCH should be transmitted, via an RRC message and dynamicsignaling (e.g., PRI). If at least one of symbols indicated for PDSCHreception overlaps flexible symbols indicated in semi-static DL/ULassignment information, and PDCCH monitoring is not configured (orassigned) in a symbol immediately preceding symbols in which PDSCH is tobe transmitted, the terminal may determine the corresponding slot as aslot for PDSCH transmission so as to transmit PDSCH in the correspondingslot. If PDCCH monitoring is configured (or assigned) in the symbolimmediately preceding the symbols indicated for PDSCH reception, theterminal may defer PDSCH transmission to a subsequent available slotwithout transmitting PDSCH in the corresponding slot. In other words,the terminal may recognize symbols in which PDSCH is to be transmittedin every slot, via an RRC message and/or dynamic signaling (e.g., PRI).If even at least one of the recognized symbols overlaps the DL symbol ofthe semi-static DL/UL assignment information, or PDCCH monitoring isconfigured in the symbol immediately preceding the symbols in whichPDSCH is to be transmitted, the terminal does not transmit PDSCH in thecorresponding slot and, otherwise, the terminal transmits PDSCH in thecorresponding slot. This is because a switching gap between DL and ULmay be needed. PDSCH that has failed to be transmitted may be deferredso as to be transmitted in a subsequent available slot.

As another example, an SS/PBCH block may be configured to overlap a DLsymbol, a flexible symbol, and a UL symbol of semi-static DL/ULassignment information relating to the terminal. In this case, theterminal may consider a symbol overlapping the SS/PBCH block as asemi-static DL symbol. That is, if a semi-static UL symbol is configuredto the terminal, and the SS/PBCH block overlaps the symbol, the terminalmay assume that the symbol is configured as a semi-static DL symbol.Additionally, if a symbol immediately subsequent to the symbolsoverlapping the SS/PBCH block is a semi-static UL symbol, the terminalmay assume that the semi-static UL symbol corresponds to semi-staticflexible symbols.

When describing whether to perform PDSCH transmission and deferral,descriptions have been provided based on at least one symbol inconsideration of a symbol immediately preceding symbols for PDSCHtransmission. However, a DL-UL switching gap may be configured variouslyaccording to configurations of a base station and a terminal, andtherefore whether to perform PDSCH transmission and deferral may be, ofcourse, determined in consideration of one or more symbols.

Eighth Embodiment

The eighth embodiment relates to a situation in which a gap between a DLsymbol requiring downlink reception and a UL symbol requiring uplinktransmission is insufficient, and therefore a terminal is unable toperform downlink reception and uplink transmission. At least a DL-ULswitching gap is required between downlink reception and uplinktransmission of the terminal. Here, the DL-UL switching gap may bedescribed interchangeably with a switching gap, or simply a gap.

A length of the DL-UL switching gap may vary depending on a carrierfrequency. For example, if a frequency of a carrier is 6 GHz or lower(hereinafter, referred to as frequency range (FR) 1), the DL-ULswitching gap may require 13 us. Alternatively, if the frequency of thecarrier is 6 GHz or higher (hereinafter, referred to as FR2), the DL-ULswitching gap may require 7 us.

The DL-UL switching gap is also affected by a timing advance (TA) valueand a TA offset value. The DL-UL switching gap may be affected bysubcarrier spacing (SCS). That is, the DL-UL switching gap may bedetermined based on a TA value and a TA offset value and/or subcarrierspacing. For example, when a length (duration) of one symbol is X us, asymbol (G) necessary for the DL-UL switching gap may be given asG=ceil((Rx2Tx+TA+TA_offset)/X). Here, Rx2Tx is time taken for an RFcircuit to switch from reception to transmission, and a value thereofmay vary depending on a frequency of a carrier. If a frequency of acarrier is 6 GHz or lower (FR1), Rx2Tx may be 13 us, and if frequency ofa carrier is 6 GHz or higher (FR2), Rx2Tx may be 7 us. TA may be a TAvalue configured for the terminal by the base station or may be amaximum value among TA values configurable for the terminal by the basestation. TA_offset may be 39936*Tc or 25600*Tc in FR1 and may be13792*Tc in FR2. Here, Tc=1/(480*103*4096). Here, the switching gap maybe an RF interruption time.

Table 3 is an example of the number of symbols required for a DL-ULswitching gap according to subcarrier spacing.

TABLE 3 Subcarrier spacing configuration for the active UL BWP G 15 kHzor 30 kHz  1 60 kHz or 120 kHz 2

Table 4 is another example of the number of symbols required for a DL-ULswitching gap according to subcarrier spacing.

TABLE 4 Subcarrier spacing configuration for the active UL BWP G 15 kHzor 30 kHz  2 60 kHz or 120 kHz 2

Hereinafter, a method of processing transmission of an uplink channel oran uplink signal on the basis of a downlink signal received by aterminal and a UL-DL switching gap (G) will be described. A downlinksignal may include an SS/PBCH block, PDSCH, PDCCH, a periodic signal, ameasurement signal, and the like. An uplink channel may include PUSCH,PUCCH, PRACH, and the like, and an uplink signal may include an SRS, aperiodic signal, a measurement signal, and the like.

(Method 1)—Symbol for SS/PBCH Block Transmission and Uplink Transmission

Method 1 is a method of processing uplink transmission by a terminal, inwhich the terminal may determine whether at least one of symbolsindicated for transmission of an uplink channel or transmission of anuplink signal is configured to overlap (i.e., to be contradicted to)symbols (or symbols for SS/PBCH block transmission) indicated to receivean SS/PBCH block from a base station, and may transmit the uplinkchannel or the uplink signal on the basis of the determination. Here, ifat least some of the symbols in which the SS/PBCH block is received isconfigured to overlap transmission of the uplink channel or transmissionof the uplink signal, the terminal does not transmit the uplink channelor the uplink signal and, otherwise, the terminal transmits the uplinksignal.

Method 1 is another method of processing uplink transmission by aterminal, in which the terminal may determine whether at least one ofsymbols indicated for transmission of an uplink channel or transmissionof an uplink signal is configured to overlap a symbol(s) to which anSS/PBCH block indicated to be received from a base station is assigned,and may transmit the uplink channel or the uplink signal on the basis ofthe determination. Here, if at least some of G symbol(s) are configuredto overlap transmission of the uplink channel or transmission of theuplink signal, the terminal does not transmit the uplink channel or theuplink signal and, otherwise, the terminal transmits the uplink signal.

(Method 2)—Symbol for Downlink Transmission and Uplink Transmission

Method 2 is a method of processing uplink transmission by a terminal, inwhich the terminal may determine whether at least one of symbolsindicated for transmission of an uplink channel or transmission of anuplink signal is configured to overlap symbols (or symbols for downlinktransmission) indicated to receive downlink transmission from a basestation, and may transmit the uplink channel or the uplink signal on thebasis of the determination. Here, if at least some of the symbols inwhich downlink transmission is received are configured to overlaptransmission of the uplink channel or transmission of the uplink signal,the terminal does not transmit the uplink channel or the uplink signaland, otherwise, the terminal transmits the uplink signal.

Method 2 is another method of processing uplink transmission by aterminal, in which the terminal may determine whether at least one ofsymbols indicated for transmission of an uplink channel or transmissionof an uplink signal is configured to overlap G symbol(s) subsequent tosymbol(s) indicated for reception of downlink transmission from a basestation, and may transmit the uplink channel or the uplink signal on thebasis of the determination. Here, if at least some of G symbol(s) areconfigured to overlap transmission of the uplink channel or transmissionof the uplink signal, the terminal does not transmit the uplink channelor the uplink signal and, otherwise, the terminal transmits the uplinksignal.

In addition to the described method, the base station may performscheduling (e.g., dynamic scheduling of layer 1 (L1)) so that symbolsfor downlink transmission and symbols for uplink transmission do notoverlap each other. That is, when the base station performs schedulingfor the terminal, uplink transmission based on symbol G may beconfigured. In this case, the terminal may not expect the base stationto configure uplink transmission of the terminal in symbol G.

If uplink transmission based on an RRC configuration instead of dynamicscheduling of L1 is configured, the terminal may determine whetheruplink transmission configured via RRC overlaps symbol G, and theterminal may or may not perform transmission of an uplink channel orsignal on the basis of the determination.

Hereinafter, a method in which a terminal processes downlink receptionand transmission of an uplink channel (or uplink signal) on the basis ofa UL-DL switching gap (G) is described. A downlink signal may include anSS/PBCH block, PDSCH, PDCCH, CSI-RS, and the like. An uplink channel mayinclude PUSCH, PUCCH, PRACH, and the like, and an uplink signal mayinclude an SRS, and the like.

(Method 3)—Processing of Downlink Signals According to Whether FlexibleSymbol and Uplink Signal Overlap

In symbols that are configured by flexible symbols by semi-static DL/ULassignment information or symbols that are not configured by semi-staticDL/UL assignment information, the terminal may receive or may fail toreceive a downlink signal configured by a UE-specific RRC message (e.g.,downlink periodic signal or measurement signal). In this case, theterminal may process the configured downlink reception, based on anarrangement relationship (e.g., overlapping relationship) between theUL-DL switching gap and the uplink signal.

When describing a method of processing the configured downlink receptionby the terminal, the terminal may determine whether the terminal isconfigured to transmit an uplink signal in G symbol(s) subsequent to alast symbol of the configured downlink signal, and may receive theconfigured downlink signal on the basis of the determination. Here, as aresult of the determination, if the uplink signal does not overlap in Gsymbol(s) subsequent to the last symbol of the configured downlinksignal, the terminal may receive the configured downlink signal. On thecontrary, if the uplink signal overlaps in G symbol(s), the terminaldoes not receive the configured downlink signal. That is, if there arenot at least G gap symbols between the last DL symbol configured by thesemi-static DL/UL assignment information and the first symbol assignedto the uplink signal in one slot, the terminal drops the downlinksignal.

The uplink signal may include an uplink signal configured by acell-specific RRC message. For example, the uplink signal configured bythe cell-specific RRC message may include PRACH.

The uplink signal may include an uplink signal indicated by L1signaling. For example, the uplink signal indicated by L1 signaling mayinclude PUSCH scheduled with DCI format 0_0 or 0_1. The uplink signalindicated by L1 signaling may include PUCCH including an HARQ-ACKresponse of PDSCH scheduled by DCI format 1_0 or 1_1. The uplink signalindicated by L1 signaling may include an SRS signal indicated by DCI.The uplink signal indicated by L1 signaling may include firsttransmission of uplink semi-persistent scheduled (SPS) PDSCHtransmissions indicated by DCI scrambled with CS-RNTI.

The downlink signal may include a CSI-RS configured by a UE-specific RRCmessage. For example, the downlink signal may include CORESET for PDCCHmonitoring configured by the UE-specific RRC message. The downlinksignal may include downlink SPS PDSCH transmission (excluding the firsttransmission) scrambled with a CS-RNTI.

In another method of processing the downlink reception by the terminal,the terminal may determine whether a UL symbol configured by semi-staticDL/UL assignment information overlaps in G symbol(s) subsequent to thelast symbol of the downlink signal, and may receive a downlink signal onthe basis of the determination. As a result of the determination, if theUL symbol configured by the semi-static DL/UL assignment informationoverlaps in G symbol(s), the terminal does not receive the downlinksignal and, otherwise, the terminal receives the downlink signal. Thatis, if there are not at least G gap symbols between the last DL symbolconfigured by the semi-static DL/UL assignment information and the firstsymbol allocated to the uplink signal in one slot, the terminal dropsthe downlink signal.

In another method of processing the configured downlink reception by theterminal, the terminal may determine whether a UL symbol indicated bydynamic SFI overlaps in G symbol(s) subsequent to a last symbol of theconfigured downlink signal, and may receive the configured downlinksignal on the basis of the determination. As a result of thedetermination, if the UL symbol indicated by the dynamic SFI overlaps inG symbol(s), the terminal does not receive the configured downlinksignal and, otherwise, the terminal receives the downlink signal. Thatis, if there are not at least G gap symbols between the last DL symbolconfigured by the semi-static DL/UL assignment information and the firstsymbol allocated to the uplink signal in one slot, the terminal dropsthe downlink signal.

In another method of processing the configured downlink reception by theterminal, the terminal may determine whether the DL symbol configured bythe semi-static DL/UL assignment information overlaps in G symbol(s)preceding a first symbol of the uplink signal, and the terminal mayreceive the configured downlink signal on the basis of thedetermination. As a result of the determination, if the DL symbolconfigured by the semi-static DL/UL assignment information overlaps in Gsymbol(s), the terminal does not receive the configured downlink signaland, otherwise, the terminal receives the configured downlink signal.That is, if there are not at least G gap symbols between the last DLsymbol configured by the semi-static DL/UL assignment information andthe first symbol allocated to the uplink signal in one slot, theterminal drops the downlink signal.

In another method of processing the configured downlink reception by theterminal, the terminal may determine whether the DL symbol indicated bythe dynamic SFI overlaps in G symbol(s) preceding the first symbol ofthe uplink signal, and may receive the configured downlink signal on thebasis of the determination. As a result of the determination, if the DLsymbol indicated by the dynamic SFI overlaps in G symbol(s), theterminal does not receive the configured downlink signal and, otherwise,the terminal receives the configured downlink signal. That is, if thereare not at least G gap symbols between the last DL symbol configured bythe semi-static DL/UL assignment information and the first symbolassigned to the uplink signal in one slot, the terminal drops thedownlink signal.

The aforementioned method of processing uplink transmission by theterminal may include an operation wherein the terminal does not expectthe uplink signal to be configured or indicated by L1 signaling during Gsymbols subsequent to the downlink signal (downlink periodic signal ormeasurement signal) configured by the UE-specific RRC message, insymbols configured by flexible symbols by semi-static DL/UL assignmentinformation or in symbols that are not configured by semi-static DL/ULassignment information.

(Method 4)—Processing of Uplink Signals According to Whether FlexibleSymbol and Downlink Signal Overlap

In symbols configured by flexible symbols by semi-static DL/ULassignment information or symbols that are not configured by semi-staticDL/UL assignment information, the terminal may transmit or may fail totransmit an uplink signal configured by a UE-specific RRC message (e.g.,uplink periodic signal or measurement signal). In this case, the methodof processing the uplink transmission by the terminal may include makinga determination based on an arrangement relationship (e.g., overlappingrelationship) between the UL-DL switching gap and the downlink signal.

In a method of processing the configured uplink transmission by theterminal, the terminal may transmit the configured uplink signal, basedon whether the terminal receives the downlink signal in G symbol(s)preceding a first symbol of the configured uplink signal. That is, ifthe downlink signal does not overlap in G symbol(s) preceding the firstsymbol of the configured uplink signal, the terminal may transmit theconfigured uplink signal. On the contrary, if the downlink signaloverlaps in G symbol(s), the terminal does not transmit the configureduplink signal. That is, if there are not at least G gap symbols betweenthe first UL symbol configured by semi-static DL/UL assignmentinformation and the last symbol assigned to the downlink signal in oneslot, the terminal drops the uplink signal.

Here, the downlink signal may include a downlink signal configured by acell-specific RRC message. The downlink signal configured by thecell-specific RRC message may include an SS/PBCH block. The downlinksignal configured by the cell-specific RRC message may include type-0common search space. Here, the type-0 common search space is a searchspace for receiving remaining minimum scheduling information (RMSI). Thedownlink signal configured by the cell-specific RRC message may includea type-0A common search space. The type-0A common search space is asearch space for receiving a response of PRACH during a random accessprocedure.

The downlink signal may include a downlink signal indicated by L1signaling. For example, the uplink signal indicated by L1 signaling mayinclude PDSCH scheduled by DCI format 1_0 or 1_1. The uplink signalindicated by L1 signaling may include an aperiodic CSI-RS indicated byDCI. The uplink signal indicated by L1 signaling may include firsttransmission of uplink semi-persistent scheduled (SPS) PDSCHtransmissions indicated by DCI scrambled with CS-RNTI.

The uplink signal may include an SRS configured by the UE-specific RRCmessage. The uplink signal may include periodic PUCCH and PUSCHconfigured by the UE-specific RRC message. The uplink signal may includean SR configured by the UE-specific RRC message.

In another method of processing the configured uplink transmission bythe terminal, the terminal may determine whether the DL symbolconfigured by the semi-static DL/UL assignment information overlaps in Gsymbol(s) preceding a first symbol of the configured uplink signal, andthe terminal may transmit the configured uplink signal on the basis ofthe determination. As a result of the determination, if the DL symbolconfigured by semi-static DL/UL assignment information does not overlapin G symbol(s), the terminal transmits the configured uplink signal and,otherwise, the terminal does not transmit the configured uplink signal.That is, if there are not at least G gap symbols between the first ULsymbol configured by semi-static DL/UL assignment information and thelast symbol assigned to the downlink signal in one slot, the terminaldrops the uplink signal.

The aforementioned method may additionally include an operation whereinthe terminal does not expect the downlink signal to be configured orindicated by L1 signaling during G symbols subsequent to the downlinksignal (downlink periodic signal or measurement signal) configured bythe UE-specific RRC message, in symbols configured by flexible symbolsby semi-static DL/UL assignment information or in symbols that are notconfigured by semi-static DL/UL assignment information.

In symbols configured by flexible symbols by semi-static DL/ULassignment information or symbols that are not configured by semi-staticDL/UL assignment information, if the number of symbols between the lastsymbol of the downlink signal configured by a cell-specific RRC messageor indicated by L1 signaling and the first symbol of the uplink signalconfigured by the cell-specific RRC message or indicated by L1 signalingis less than G, the operation of the terminal is as follows.

The terminal may receive a downlink signal configured by thecell-specific RRC message but may not transmit an uplink signalconfigured by the cell-specific RRC message or indicated by L1signaling.

The terminal may transmit an uplink signal configured by thecell-specific RRC message and may not receive a downlink signalconfigured by the cell-specific RRC message or indicated by L1signaling.

The terminal may operate according to L1 signaling. That is, if L1signaling indicates downlink reception and the cell-specific RRC messageconfigures uplink transmission, the terminal may perform downlinkreception and may not perform uplink transmission. Conversely, if L1signaling indicates uplink reception and the cell-specific RRC messageconfigures downlink transmission, the terminal may perform uplinktransmission and may not perform downlink reception.

Hereinafter, in the present specification, reception of asynchronization signal block (SSB) in an SS block-based RRM measurementtiming configuration (SMTC) will be described.

A terminal should be able to perform measurement without a measurementgap when an SSB is completely included in an active bandwidth part ofthe terminal. If a subcarrier spacing of a measurement signal isdifferent from PDSCH/PDCCH, or in frequency range FR2, there may belimitations in scheduling flexibility.

Specifically, if a subcarrier spacing of a measurement signal infrequency range FR1 is the same as PDSCH/PDCCH, there is no limitationin scheduling availability. However, if the subcarrier spacing of themeasurement signal in frequency range FR1 is different from PDSCH/PDCCH,there may be a scheduling availability limitation, which will bedescribed later. First, if the terminal is able to receive a data signaland an SSB having different subcarrier spacings (that is, if theterminal supports simultaneousRxDataSSB-DiffNumerology), there is noscheduling availability limitation. Conversely, if the terminal isunable to receive a data signal and a synchronization signal block (SSB)having different subcarrier spacings (that is, if the terminal does notsupport simultaneousRxDataSSB-DiffNumerology), the terminal has limitedscheduling availability. In this case, the following schedulingavailability limitations are applied for SS-RSRP/RSRQ/SINR measurement.

i) If deriveSSB_IndexFromCell is enabled, the terminal expects neitherto receive PDCCH/PDSCH nor to transmit PUCCH/PUSCH in consecutive SSBsymbols and one symbol immediately preceding and one symbol immediatelysubsequent to the consecutive SSB symbols within an SMTC window.

ii) If deriveSSB_IndexFromCell is disabled, the terminal expects neitherto receive PDCCH/PDSCH nor to transmit PUCCH/PUSCH in all symbols withinthe SMTC window.

deriveSSB_IndexFromCell indicates whether the UE, in order to derive anSSB index of a cell for an indicated SSB frequency and subcarrierspacing, can use a timing of a cell having the same SSB frequency andsubcarrier spacing.

The following scheduling availability limitations are applied forSS-RSRP/SINR measurement in frequency range FR2.

i) The terminal expects neither to receive PDCCH/PDSCH nor to transmitPUCCH/PUSCH in consecutive SSB symbols and one symbol immediatelypreceding and one symbol immediately subsequent to the consecutive SSBsymbols within the SMTC window.

The following scheduling availability limitations are applied forSS-RSRQ measurement in frequency range FR2.

i) The terminal expects neither to receive PDCCH/PDSCH nor to transmitPUCCH/PUSCH in consecutive SSB symbols, RSSI measurement symbols, andone symbol immediately preceding and one symbol immediately subsequentto the consecutive SSB/RSSI symbols within the SMTC window.

In the above description, the SMTC window follows smtc2 if smtc2 isconfigured from a higher layer and, otherwise, the SMTC window followssmtc1.

The present specification describes a method of determining, when thereis a limitation on scheduling availability for reception of ameasurement signal, a slot for repetition transmission of PUCCHaccording to the scheduling availability limitation. Specifically, whenthe terminal is configured to repeatedly transmit PUCCH K times, theterminal needs to determine K slots for repetition transmission ofPUCCH.

The terminal is configured with carrier aggregation or dual connectivityfor transmission of two or more cells in a bundle, wherein it is assumedthat two cells are configured for convenience. The following descriptionis applicable even when two or more cells are configured. One of twocells is a Pcell, and the Pcell is a cell in which the terminaltransmits PUCCH. The other one of the two cells is an Scell, and theScell is a cell in which the terminal does not transmit PUCCH. Ameasurement signal may be configured in an Scell.

The terminal may be set/configured with MeasObjectNR IE (informationelement) from a higher layer. MeasObjectNR IE includes information forintra/inter-frequency measurement. ssbFrequency included in MeasObjectNRIE informs of a frequency of an SSB, ssbFrequencySpacing informs of asubcarrier spacing of an SSB, and ssb-ToMeasure informs of configurationinformation on a time domain of an SSB to be measured. smtc1 or smtc2included in MeasObjectNR IE informs of a configuration of the SMTCwindow.

The following is a method of determining K slots for transmission ofPUCCH when the terminal is set/configured to repeatedly transmit PUCCHin K slots. i) If symbols to which PUCCH transmission is assigned in oneslot overlap a measurement signal (SSB configured in MeasObjectNR)within the SMTC window, the terminal does not include the slot in Kslots for transmission of PUCCH. ii) If symbols to which PUCCHtransmission is assigned in one slot overlap a measurement signal (SSBconfigured in MeasObjectNR) in one symbol immediately subsequent to themeasurement signal within the SMTC window, the terminal does not includethe slot in K slots for transmission of PUCCH. iii) If symbols to whichPUCCH transmission is assigned in one slot overlap a measurement signal(SSB configured in MeasObjectNR) in one symbol immediately subsequent toor one symbol immediately preceding the measurement signal within theSMTC window, the terminal does not include the slot in K slots fortransmission of PUCCH. The described i) to iii) are applicable only whenscheduling availability is limited.

The following is method of PUCCH transmission within the SMTC windowafter the terminal is set/configured to repeatedly transmit PUCCH in Kslots and determines K slots for transmission of PUCCH. i) If symbols towhich PUCCH transmission is assigned in one slot overlap a measurementsignal (SSB configured in MeasObjectNR) and one symbol immediatelysubsequent to the measurement signal within the SMTC window, theterminal does not transmit PUCCH in the slot. ii) If symbols to whichPUCCH transmission is assigned in one slot overlap a measurement signal(SSB configured in MeasObjectNR) and one symbol immediately subsequentto the measurement signal within the SMTC window, the terminal does nottransmit PUCCH in the slot. iii) If symbols to which PUCCH transmissionis assigned in one slot overlap a measurement signal (SSB configured inMeasObjectNR) and one symbol immediately subsequent to or one symbolimmediately preceding the measurement signal within the SMTC window, theterminal does not transmit PUCCH in the slot. The described i) to iii)are applicable only when scheduling availability is limited.

The present specification describes a method of determining a slot forrepetition PUCCH transmission when the terminal has only half-duplexcapability. If the terminal has only half-duplex capability, theterminal cannot perform transmission and reception at the same time.That is, when the terminal performs transmission in one cell, theterminal cannot perform reception in another cell. Similarly, when theterminal performs reception in one cell, the terminal cannot performtransmission in another cell. Therefore, the terminal should operate inonly one direction of transmission and reception in one cell.

The present specification provides descriptions of a method of, whenthere is a measurement signal that a terminal should receive in aPcell/Scell, and the terminal is set/configured to repeatedly transmitPUCCH in K slots in the Pcell, determining K slots for transmission ofPUCCH by the terminal. If a terminal determines, without considering ameasurement signal required to be received in a Pcell/Scell, K slots fortransmission of PUCCH in the Pcell, the terminal should transmit PUCCHin the Pcell and should receive a measurement signal in the Pcell/Scellin some slots. This operation is possible for a terminal having afull-duplex capability, but there is a problem in that this operation isnot possible for a terminal having only a half-duplex capability.Therefore, the terminal should consider a measurement signal of thePcell/Scell, to determine a slot in which PUCCH is to be transmitted.

In a method in which a terminal having a half-duplex capabilitydetermines K slots for repetition transmission of PUCCH, the terminalmay, if symbols to which PUCCH transmission is assigned in one slotoverlap a measurement signal of a Pcell/Scell within an SMTC window,exclude the slot from K slots in which PUCCH is to be repeatedlytransmitted.

In a method in which a terminal having a half-duplex capabilitydetermines K slots for repetition transmission of PUCCH, the terminalmay, if symbols to which PUCCH transmission is assigned in one slotoverlap a measurement signal of a Pcell/Scell and a symbol immediatelysubsequent to the measurement signal within an SMTC window, exclude theslot from K slots in which PUCCH is to be repeatedly transmitted.

In a method in which a terminal having a half-duplex capabilitydetermines K slots for repetition transmission of PUCCH, the terminalmay, if symbols to which PUCCH transmission is assigned in one slotoverlap a measurement signal of a Pcell/Scell and a symbol immediatelysubsequent to or a symbol immediately preceding the measurement signalwithin an SMTC window, exclude the slot from K slots in which PUCCH isto be repeatedly transmitted.

The measurement signal may include an SSB configured in MeasObjectNR.The measurement signal may include a CSI-RS configured in MeasObjectNR.The CSI-RS may be configured via csi-rs-ResourceConfigMobility inMeasObjectNR IE.

In 3GPP NR Rel-16 enhanced URLLC (eURLLC), a technology for providing aservice with high reliability as well as low latency will be introduced.In particular, in a case of uplink, a method in which a terminalrepeatedly transmits a physical uplink shared channel (PUSCH) to a basestation as quickly as possible so as to reduce a delay time and increasereliability may be supported. Hereinafter, the present specificationdescribes a method in which a terminal repeatedly transmits a physicaluplink data channel as quickly as possible.

A terminal receives scheduling information of PUSCH from a base stationthrough PDCCH (or DCI). The terminal transmits PUSCH in uplink, based onthe received scheduling information. The terminal may recognize atime-frequency resource in which PUSCH is to be transmitted, by usingtime domain assignment information (time domain resource assignment) andfrequency domain assignment information (frequency domain resourceassignment) for PUSCH transmission, which are included in DCI. A timeresource in which PUSCH is transmitted includes consecutive symbols, andone PUSCH cannot be scheduled across a slot boundary.

3GPP NR Rel-15 supports repetition PUSCH transmission between slots.First, the terminal may receive a configured number of repetitiontransmissions from the base station. For example, a value configured forthe terminal is assumed to be K. When the terminal receives PDCCH (orDCI) for scheduling of PUSCH in slot n and is indicated/configured totransmit PUSCH in slot n+k, the terminal may transmit PUSCH in Kconsecutive slots starting from slot n+k. That is, the terminal maytransmit PUSCH in slot n+k, slot n+k+1, . . . , slot n+k+K−1. Time andfrequency resources in which PUSCH is transmitted in each slot are thesame as those indicated/configured via DCI. That is, PUSCH may betransmitted in the same symbol and the same PRB in a slot. In order toobtain a diversity gain in the frequency domain, frequency hopping maybe configured for the terminal. Frequency hopping includes intra-slotfrequency hopping in which frequency hopping is performed within a slotand inter-slot frequency hopping in which frequency hopping is performedfor each slot. If intra-slot frequency hopping is configured for theterminal, the terminal divides PUSCH in half in the time domain in eachslot, then transmits one half in a scheduled PRB, and transmits theother half in a PRB obtained by adding an offset value to the scheduledPRB. Here, for the offset value, two or four values may be configuredvia a higher layer, and one of the values may be indicated via DCI. Ifinter-slot frequency hopping is configured for the terminal, theterminal transmits PUSCH in a scheduled PRB in an odd-numbered slot inwhich PUSCH is transmitted, and transmits PUSCH in a PRB obtained byadding an offset value to the scheduled PRB in an even-numbered slot.When the terminal performs repetition transmission in a slot, if asymbol in which PUSCH should be transmitted is configured by asemi-static DL symbol in a specific slot, the terminal does not transmitPUSCH in the slot. PUSCH that has failed to be transmitted is deferredto another slot and is not transmitted.

The described repetition transmission of Rel-15 is not suitable forproviding an eURLLC service. This is because there are problems that i)it is difficult to provide high reliability, and ii) a delay time islong. Specifically, if one slot includes 14 symbols and PUSCH istransmitted in symbols 12 and 13, PUSCH should be repeatedly transmittedin symbols 12 and 13 also in a subsequent slot. Therefore, althoughPUSCH transmission is possible in symbols 1 to 11 in the subsequentslot, transmission is not performed and it is thus difficult to obtainhigh reliability. In addition, it is assumed that one slot includes 14symbols, and PUSCH is transmitted in symbols 0 to 13 in order to obtainhigh reliability. In order for the base station to successfully receivePUSCH, a last symbol of PUSCH, i.e., symbol 13, should be received.Therefore, there occurs a problem that a delay time becomes longeraccording to a length of PUSCH.

To solve this problem, in the present specification, a method ofrepeatedly transmitting PUSCH in one slot will be described.Specifically, a terminal may continuously and repeatedly transmitscheduled PUSCH. Continuous means that PUSCH is transmitted again from asymbol immediately after one PUSCH ends. This may be described asmini-slot-level PUSCH repetition, and the aforementioned 3GPP NR Rel-15repetition transmission method may be described as slot-level PUSCHrepetition.

When the mini-slot-level PUSCH repetition method is applied, theabove-described problem can be solved. Specifically, i) high reliabilitymay be provided. For example, if one slot includes 14 symbols and PUSCHis transmitted in symbols 12 and 13, PUSCH may be repeatedly transmittedin symbols 1 and 2 in a subsequent slot. Therefore, since PUSCH isdirectly and continuously transmitted, high reliability can be obtained.In addition, ii) a delay time may be decreased. For example, it isassumed that one slot includes 14 symbols, and PUSCH is transmitted insymbols 0 to 1 in order to obtain high reliability. Since PUSCH isrepeatedly transmitted in a slot, PUSCH may be transmitted in symbols2-3 and may be repeatedly transmitted in symbols 4-5. Accordingly,reliability similar to that of PUSCH transmission in which a length ofone slot is 14 may be obtained. However, in this case, the base stationmay achieve reception success not only when all repetition transmissionsare received according to a channel situation, but the base station mayachieve reception success in the middle of repetition transmission.Accordingly, after symbol 2 in which first repetition transmission ends,the terminal may successfully receive PUSCH depending on a situation, sothat a delay time can be reduced.

Hereinafter, a case in which mini-slot-level PUSCH repetition isrepeatedly transmitted in another slot across a slot will be described.As described above, in mini-slot-level PUSCH repetition, subsequentrepetition transmission of PUSCH starts from a symbol immediatelyfollowing the end of one PUSCH transmission. However, continuoustransmission may not be possible in the following situations.

i) First, a case where, when repetition PUSCH transmission is performedfrom a symbol immediately subsequent to a symbol in which first PUSCHtransmission ends, symbols for PUSCH transmission and a semi-static DLsymbol overlap. In this case, due to overlapping with the semi-static DLsymbol, PUSCH cannot be transmitted from the immediately subsequentsymbol. Therefore, PUSCH may be repeatedly transmitted in anothersymbol.

ii) Next, a case where, when repetition PUSCH transmission is performedfrom a symbol immediately subsequent to a symbol in which first PUSCHtransmission ends, repeatedly transmitted PUSCH crosses a slot boundary.Since one PUSCH is not allowed to cross a slot boundary, PUSCH may betransmitted via another symbol.

In the present specification, a repetition PUSCH transmission method inconsideration of cases i) and ii) will be described.

FIG. 18 illustrates repetition mini-slot-level PUSCH transmissionaccording to an embodiment of the present disclosure.

If a terminal is configured to perform mini-slot-level PUSCH repetition,the terminal transmits PUSCH in a symbol immediately subsequent to onePUSCH transmission. If PUSCH cannot be transmitted (as described above,in the case of overlapping with a semi-static DL symbol or crossing aslot boundary), the terminal may transmit PUSCH in an earliest symbolavailable for transmission. Here, the earliest symbol available fortransmission refers to a case where PUSCH does not overlap a semi-staticDL symbol and does not cross a slot boundary. Referring to FIG. 18 , theterminal may be configured to perform transmission repeatedly 4 timeswith mini-slot-level PUSCH repetition, and may be configured/indicated,from PDCCH (or DCI), to transmit PUSCH via 4 symbols from a fifth symbolof a slot. In FIG. 18 , D, U, and F refer to a downlink symbol, anuplink symbol, and a flexible symbol in semi-static DL/UL configuration.The terminal may transmit first PUSCH in slot symbols 5 to 8, and maydetermine whether second PUSCH is transmittable in symbols 9 to 12 whichare immediately subsequent repetition PUSCH transmission periods. Iftransmission is possible (that is, if PUSCH does not overlap asemi-static DL symbol and does not cross a slot boundary), the terminalmay transmit second PUSCH in symbols 9 to 12. In this case, PUSCHstarting in symbol 13, which is a subsequent symbol of a last symbol(symbol 12) in which second PUSCH is transmitted, crosses a slotboundary and overlaps a semi-static DL symbol, third PUSCH transmissioncannot be performed. Subsequent transmittable symbols are symbols 3 to 6of the subsequent slot, and since these symbols are flexible symbols,PUSCH transmission is possible. Therefore, third repetition PUSCHtransmission is performed in the corresponding symbols. Thereafter,fourth repetition PUSCH transmission is performed in symbols 7 to 10.Since the terminal has completed 4 repetition transmissions, repetitiontransmission is no longer performed.

FIG. 19 illustrates repetition mini-slot-level PUSCH transmissionaccording to another embodiment of the present disclosure.

If a terminal is configured/indicated to perform mini-slot-level PUSCHrepetition, the terminal transmits PUSCH in a symbol immediatelysubsequent to one PUSCH transmission. If PUSCH cannot be transmitted (ifoverlapping with a semi-static DL symbol or X flexible symbolsimmediately subsequent to the semi-static DL symbol, or crossing a slotboundary), the terminal may transmit PUSCH in an earliest symbolavailable for PUSCH transmission. Here, the earliest symbol availablefor transmission refers to a symbol in which PUSCH does not overlap asemi-static DL symbol, does not overlap X flexible symbols immediatelysubsequent to the semi-static DL symbol, and does not cross a slotboundary. Referring to FIG. 19 , it is assumed that the terminal may beconfigured to perform transmission repeatedly 4 times withmini-slot-level PUSCH repetition, and may be indicated, from PDCCH (orDCI), to transmit PUSCH via 4 symbols from a fifth symbol of a slot. D,U, and F of FIG. 19 refer to a downlink symbol, an uplink symbol, and aflexible symbol in semi-static DL/UL configuration. According to FIG. 19, the terminal may transmit PUSCH in symbols 5 to 8 of a first slot, andmay determine whether PUSCH is transmittable in symbols 9 to 12 whichare immediately subsequent repetition PUSCH transmission periods. Iftransmission is possible (that is, if PUSCH does not overlap asemi-static DL symbol, does not overlap X flexible symbols immediatelysubsequent to the semi-static DL symbol, and does not cross a slotboundary), the terminal may perform second repetition PUSCH transmissionin symbols 9 to 12. A third PUSCH transmission duration starting fromsubsequent symbol 13 crosses a slot boundary and overlaps a semi-staticDL symbol, so that third PUSCH cannot be transmitted. FIG. 19(a) is acase where X=1, and FIG. 19(b) is a case where X=2. Referring to FIG.19(a), a subsequent duration in which PUSCH is transmittable is symbol 4to symbol 7 of a subsequent slot. These symbols are flexible symbols,and transmission is thus possible. Therefore, third repetition PUSCHtransmission is performed in the corresponding symbols. Fourthrepetition PUSCH transmission is performed in symbols 8 to 11. Since theterminal has completed 4 repetition transmissions, repetitiontransmission is no longer performed. Referring to FIG. 19(b), asubsequent duration in which PUSCH is transmittable is symbol 5 tosymbol 8 of a subsequent slot. These symbols are flexible symbols orsemi-static UL symbols, and transmission is thus possible. Therefore,third repetition PUSCH transmission is performed in the correspondingsymbols. Fourth repetition PUSCH transmission is performed in symbols 9to 12. Since the terminal has completed 4 repetition transmissions,repetition transmission is no longer performed.

If an SS/PBCH block is configured in a cell for repetition PUSCHtransmission, or if an SS/PBCH block for measurement is configured inanother cell and measurement is required to be performed, the terminalprocesses symbols corresponding to the SS/PBCH block in the same way asa semi-static DL symbol. For example, as described above, a case wherePUSCH cannot be transmitted may include a symbol overlapping an SS/PBCHblock and X flexible symbols immediately subsequent to the symboloverlapping the SS/PBCH block, in addition to a case of overlapping asemi-static DL symbol or X flexible symbols immediately subsequent tothe semi-static DL symbol or crossing a slot boundary.

The terminal configured to repeatedly transmit PUSCH K times may, untilPUSCH is transmitted K times, defer PUSCH until symbols available fortransmission are found. However, deferring PUSCH for too long does notmeet the purpose of mini-slot-level PUSCH repetition. Mini-slot-levelPUSCH repetition is a method for supporting an uplink URLLC service, andif PUSCH is deferred for too long, this goes against requirements of theURLLC service. In addition, an operation of PUSCH transmission caused bydeferring of PUSCH for too long prevents a base station from using acorresponding resource for other terminals, so that there is a problemthat network resources are wasted. Therefore, in the presentspecification, a condition of terminating repetition transmission inmini-slot-level PUSCH repetition will be described.

FIG. 20 is a diagram illustrating a condition in which repetitionmini-slot-level PUSCH transmission ends according to an embodiment ofthe present disclosure.

i) If new PUSCH having the same HARQ process number (HPN) as repeatedlytransmitted PUSCH is scheduled, a terminal may stop preceding PUSCHrepetition. Specifically, referring to FIG. 20(a), schedulinginformation for scheduling of repeatedly transmitted PUSCH includesHPN=. If another PDCCH (or DCI) (DCI format 0_0 or 0_1) for schedulingof PUSCH has the same HPN (HPN=i) as the HPN, or a new data indication(NDI) is toggled additionally, repetition PUSCH transmission may not beperformed after PDCCH. A processing time is required to receive PDCCHand cancel PUSCH so that, after a last symbol of PDCCH, PUSCH before apredetermined time may not be cancelled and only PUSCH after thepredetermined time may be cancelled.

ii) If another PUSCH is scheduled in the same symbol of repeatedlytransmitted PUSCH, the terminal may not perform repetition transmissionof the PUSCH. Referring to FIG. 20(b), if PDCCH is scheduled to overlappreviously scheduled PUSCH in the time domain, repetition transmissionof PUSCH may be terminated.

iii) If the terminal receives explicit HARQ-ACK for repeatedlytransmitted PUSCH, the terminal may no longer perform repetitiontransmission. Explicit HARQ-ACK refers to information notified to theterminal by the base station through a separate channel so as toindicate whether PUSCH transmission is successfully performed.

iv) The terminal may no longer transmit repeatedly transmitted PUSCHafter a predetermined time. For example, if the requirements of theURLLC service via which PUSCH is transmitted is to finish transmissionwithin 1 ms, the terminal may no longer transmit PUSCH after 1 ms. Thepredetermined time may be an absolute time, such as 1 ms, or may bedetermined according to slots, such as 2 slots. The predetermined timeis a value configurable by the base station.

The terminal set/configured to transmit PUSCH repeatedly K times maycount the number of PUSCHs repeatedly transmitted K times.Conventionally, the terminal increases the number of repeatedlytransmitted PUSCHs only when PUSCH is actually transmitted. However, asdescribed above, an excessively long delay may occur to transmit PUSCH Ktimes. In order to solve this problem, in the present specification, acounting rule will be described.

FIG. 21 is a diagram illustrating a counting rule of repetitionmini-slot-level PUSCH transmission according to an embodiment of thepresent disclosure.

i) A terminal counts the number of PUSCHs when PUSCH is actuallytransmitted. The terminal performs counting if PUSCH cannot betransmitted during Y symbols. If a counted value exceeds the number K ofPUSCH repetitions, PUSCH is no longer transmitted. Here, Y symbols maybe the number of symbols assigned to the PUSCH. Y symbols may be thenumber of symbols included in one slot. Y symbols may correspond to avalue set/configured from a higher layer.

FIG. 21(a) shows the number of repetition PUSCH transmissions obtainedaccording to i). Referring to FIG. 21(a), it is assumed that theterminal is configured/indicated to repeatedly transmit (K=4) PUSCH 4times, and that Y=5 is configured. The terminal has performed norepetition PUSCH transmission in a last symbol of a first slot and first4 symbols of a second slot, but has failed to perform transmission forY=5 symbols (from the last symbol of the first slot to a fourth symbolof the second slot), and therefore the terminal needs to count thenumber of PUSCHs. In symbols 4, 5, 6, and 7 of the second slot, the lastfourth repetition PUSCH transmission may be performed.

ii) The terminal counts the number of PUSCHs when PUSCH is actuallytransmitted. If repetition PUSCH transmission is not performed even oncein Z slot, the number of PUSCHs is counted. If the counted number ofPUSCHs exceeds the number K of PUSCH repetitions, the PUSCH is no longertransmitted. Here, Z slot may correspond to 1 slot. Z slot maycorrespond to a value configured from a higher layer.

FIG. 21(b) shows the number of repetition PUSCH transmissions obtainedaccording to ii). It is assumed that the terminal isconfigured/indicated to repeatedly transmit (K=4) PUSCH 4 times, andthat Z=1 is set/configured. Even if the terminal has performed norepetition PUSCH transmission in a second slot (reference numeral 3 inFIG. 21 ), the number of PUSCHs is counted because the terminal hasfailed to perform PUSCH transmission during one slot. In symbols 10, 11,12, and 13 of a third slot, the last fourth repetition PUSCHtransmission may be performed.

Referring to the 3GPP standard documents, PUSCH for transmission ofuplink data by the terminal cannot cross a slot boundary. That is, astart symbol and a last symbol of scheduled PUSCH should always belocated in the same slot. (In a case of repetition PUSCH transmission, astart symbol and a last symbol may be located in different slots, butgeneral PUSCH transmission excluding a case of repetition transmissionwill be described in this document.) Specifically, a base station mayinform a terminal of information on symbols in which PUSCH transmissionis possible, via a starting and length indication value (SLIV). SLIV mayinform about a position (expressed as S and may have one of values 0, 1,2, . . . , 13) and a length (expressed as L and may have one of values1, 2, . . . , 14) of a start symbol in a slot. In other words, an SLIVvalue has one of S+L=1, 2, . . . , 14. If a combination of S+L>14 isused, the start symbol and the last symbol cannot be located in the sameslot. For example, if S=5 and L=10, transmission starts from a 6thsymbol of a slot and has a length of 10 symbols, so that 1 symbolbecomes a first symbol of a subsequent slot. Accordingly, a start symboland an end symbol are located in different slots, which isinappropriate. SLIV may be obtained based on Equation 3 below.

[Equation 3] if (L−1)≤7 then  SLIV = 14·(L−1)+S else  SLIV =14·(14−L+1)+(14−1−S) where 0<L≤14−S,and

In order to provide the URLLC service, the base station needs to assignresources to the terminal so that PUSCH transmission starts as quicklyas possible. Sufficiently many symbols are required to be used tosatisfy reliability. However, since PUSCH cannot be scheduled beyond aslot boundary, if the number of symbols available for uplinktransmission in the current slot is not sufficient, PUSCH transmissionshould be scheduled in a subsequent slot. This is not suitable for theURLLC service due to a problem of a time delay until transmission in thesubsequent slot. In order to solve this problem, in the presentspecification, a SLIV design method enabling scheduling beyond a slotboundary will be described.

When the terminal receives an SLIV value beyond a slot boundary (i.e.,S+L>14), the terminal cannot transmit PUSCH crossing the slot boundary.Accordingly, the terminal may transmit first PUSCH in symbols includedin the front side of the slot based on the slot boundary and maytransmit second PUSCH in symbols included in the rear side of the slot.Specifically, first PUSCH having a length of L1=13−S+1 is transmitted ina duration from symbol S to symbol 13 (last symbol) of the front side ofthe slot,

-   and second PUSCH having a length of L2 may be transmitted in a    duration from symbol 0 to symbol L2−1 of the rear side of the slot.    Here, L2=L−L1. First PUSCH and second PUSCH may correspond to    repetition transmission of the same transport block (TB). If the    symbols are not available for uplink transmission, the terminal may    transmit the first PUSCH and the second PUSCH in symbols other than    the symbols. In this case, the symbols unavailable for uplink    transmission may include DL symbols determined according to    semi-static DL/UL assignment, P flexible symbols immediately    subsequent to the DL symbols, symbols corresponding to an SS/PBCH    block, and P flexible symbols immediately subsequent to symbols    corresponding to the SS/PBCH block. P may have a value of 1 or 2.

FIG. 22 is a diagram illustrating PUSCH transmission in consideration ofa slot boundary according to an embodiment of the present disclosure.

Referring to FIG. 22(a), when a start symbol is symbol 6 (S) and PUSCHwith a length of 14 is scheduled, first PUSCH with a length of 8 may betransmitted from symbol 6 to symbol 13 of a first slot, and second PUSCHwith a length of 6 may be transmitted from symbol 0 to symbol 5 of asecond slot. Referring to FIG. 22(b), if first two symbols of the secondslot are symbols in which uplink transmission cannot be performed, theterminal may not transmit PUSCH in the two symbols. Accordingly, secondPUSCH may be transmitted via 4 symbols from a third symbol of the secondslot.

As in FIG. 22(b), if there is a symbol unavailable for uplinktransmission, a length of PUSCH is reduced. To prevent this, when asymbol for PUSCH transmission overlaps a symbol in which uplinktransmission is impossible, PUSCH may be transmitted by deferringtransmission to symbols in which uplink transmission is possible,subsequent to the symbol in which uplink transmission is impossible. Forexample, referring to FIG. 22(c), if first two symbols of the secondslot are symbols in which uplink transmission cannot be performed, theterminal may transmit second PUSCH via 6 symbols, in which uplinktransmission is possible, subsequent to the two symbols. In this case,transmission of PUSCH may be delayed for a while, but the number ofsymbols assigned to PUSCH may be maintained, and deterioration ofreception performance of PUSCH may thus be prevented.

Hereinafter, an SLIV design method will be described in the presentspecification.

SLIV may be designed to satisfy the following conditions.

The position (S) of a start symbol may have one of 0, 1, . . . , 13, andthe length (L) of the entire PUSCH may have one of 1, 2, . . . , 14. Avalue of S+L may be any value from 1 to 27 without a separaterestriction. SLIV satisfying this condition may be calculated asfollows.

SLIV=S+14*(L−1) or

SLIV=L−1+14*S

When SLIV=S+14*(L−1) is used as an equation to calculate SLIV, S may beobtained using the remainder of dividing SLIV by 14 (S=SLIV mod 14), andL may be obtained by adding 1 to a quotient obtained by dividing SLIV by14. (L=floor(SLIV/14)+1). When SLIV=L−1+14*S is used as an equation tocalculate SLIV, L may be obtained by adding 1 to the remainder ofdividing SLIV by 14 (L=(SLIV mod 14)+1), and S may be obtained using aquotient obtained by dividing SLIV by 14. (S=floor(SLIV/14))

When SLIV is determined by the above method, the terminal may performscheduling beyond a slot boundary. However, when PUSCH transmission isscheduled in this way, scheduling may not be performed up to the lastsymbol of the second slot (based on a slot boundary, a front side isreferred to as a first slot and a rear side is called a second slot).This has a problem that it is not efficient in terms of a frequency useefficiency because only some symbols are used despite available symbolsin the second slot. Hereinafter, a method for solving these problemswill be described in the present specification.

The position (S) of a start symbol may have one of 0, 1, . . . , 13, andthe length (L) of the entire PUSCH may have one of 1, 2, . . . , 28. Avalue of S+L should be smaller than or equal to 28. For reference, up toL=28 is possible in this case, but since PUSCH transmitted according toSLIV is divided at a slot boundary, a length of one PUSCH is equal to orsmaller than 14 symbols. An equation for obtaining SLIV satisfying thiscondition is as shown in Equation 4.

[Equation 4] If (L−1)≤7+14 then  SLIV = 14*(L−1)+S else  SLIV =14*14+14*(28−L+1)+(14−1−S) where 0<L≤28−S

Generally speaking, the position (S) of a start symbol may have one of0, 1, . . . , B, and the length (L) of the entire PUSCH may have one of1, 2, . . . , A. A value of S+L should be smaller than or equal to A. Anequation for obtaining SLIV satisfying this condition is the same asEquation 5.

[Equation 5] If (L−1)−floor((A−(B+1))/2)≤floor(A/2) then  SLIV =(B+1)*(L−1)+S else  SLIV = (B+1)*(A−L+A−B)+(B−S) where 0<L≤A−S

If A=14 and B=13, the equation is the same as Equation 3, and if A=28,and B=13, the equation is the same as Equation 4. A may be determined asa multiple of the number of symbols included in one slot. For example,if the number of symbols included in one slot is 14, A=14, 28, 42, etc.may be determined. B may be determined as a value obtained bysubtracting 1 from a multiple of the number of symbols included in onesymbol. For example, if the number of symbols included in one slot is14, B=13, 27, 41, etc. may be determined.

An SLIV value crossing a slot boundary may be obtained by multiplying,by an integer, the length among the SLIV values in Equation 3. Theposition (S) of a start symbol may have one of 0, 1, . . . , 13, and thelength (L) of the entire PUSCH may have one of 2, 4, 6, . . . , 28. Avalue of S+L should be smaller than or equal to 28. An equation forobtaining SLIV satisfying this condition is as shown in Equation 6.Here, L=2*X may be obtained, where one of values X=1, 2, 3, . . . , 14may be obtained. This method doubles the length obtained from Equation3, thereby enabling scheduling beyond a slot boundary. In general, L=A*Xmay be obtained, where A is determined as one of two or more naturalnumbers.

[Equation 6] If (X−1)≤7 then  SLIV = 14*(X−1)+S else  SLIV =14*(14−X+1)+(14−1−S) where 0<X≤14−S

When Equation 6 is used, not only an SLIV interpretation scheme issimilar to Equation 3, but also SLIV is expressed with the same numberof bits, so that it is advantageous in terms of overhead.

According to Equation 3, a total number of possible values of SLIV are14*15/2=105, which may be expressed by 7 bits. Since 7 bits can express0, 1, . . . , 127, the remaining 23 values (127-105) according toEquation 3 are not used. In this case, a base station may performscheduling beyond a slot boundary by using 23 values that are not usedby SLIV. Specifically, when SLIV is one of unused 23 values, values ofthe position (S) and the length (L) of the start symbol may bepredetermined. For example, if SLIV is one of the 23 values, adetermination may be made so that S=7 and L=14. S and L values may beconfigured/indicated via a higher layer.

Hereinafter, the present specification provides descriptions of arepetition PUSCH transmission scheme in which mini-slot-level PUSCHrepetition and multi-segment transmission schemes are combined.

FIG. 23 to FIG. 26 are diagrams illustrating repetition PUSCHtransmission in consideration of multi-segment transmission andrepetition mini-slot-level PUSCH transmission according to an embodimentof the present disclosure.

i) Referring to FIG. 23 , a base station transmits time domain resourceassignment information (S: start symbol index, L: length) for firstrepetition PUSCH transmission of PUSCH to a terminal. Then, the number(K) of repetitions is transmitted. The terminal determines symbols inwhich repetition PUSCH transmission is performed using the receivedinformation. In this case, subsequent repetition PUSCH transmission iscontinuously performed in a symbol immediately subsequent to a symbol inwhich first repetition PUSCH transmission is performed. If onerepetition PUSCH transmission crosses a slot boundary, the repetitionPUSCH transmission may be divided based on the slot boundary. If onerepetition PUSCH transmission overlaps an SS/PBCH block or a DL symbolconfigured in a semi-static UL/DL configuration, repetition PUSCHtransmission may be performed in a symbol that does not overlap the DLsymbol. The terminal may exclude, from repetition PUSCH transmission, aflexible symbol immediately subsequent to the DL symbol configured inthe semi-static UL/DL configuration. Referring to FIG. 23 , when it isconfigured that an index of a start symbol in which first repetitionPUSCH transmission is performed is 4, a length is 4, and the number ofrepetition transmissions is 5, since third repetition PUSCH transmissioncrosses a slot boundary, the third repetition PUSCH transmission isdivided based on the slot boundary. This method may cause disadvantagesthat, when repetition PUSCH transmission is divided at the slotboundary, the number of symbols included in one repetition PUSCHtransmission is too few. In order to solve this problem, if repetitionPUSCH transmission is configured by only one symbol, the terminal maynot perform the repetition PUSCH transmission. This is because, ifrepetition PUSCH transmission is configured by only one symbol, dataother than a DM-RS cannot be transmitted in the corresponding onesymbol. If the number of symbols in which repetition PUSCH transmissionis performed is equal to or less than the number of DM-RS symbolsrequired to be transmitted via repetition PUSCH transmission, theterminal may not perform repetition PUSCH transmission.

ii) Referring to FIG. 24 , a base station transmits, to a terminal, timedomain resource assignment information (S: start symbol index, L:length) for PUSCH transmission. Then, the number (K) of repetitions istransmitted. The base station determines whether L*K symbols from astart symbol corresponding to S have crossed a slot boundary. If theslot boundary is not crossed, first repetition PUSCH transmission isconfigured by L symbols starting from the start symbol, and K−1subsequent repetition PUSCH transmissions may continuously start from asymbol immediately subsequent to the symbol in which first repetitionPUSCH transmission is performed, and may be configured by L symbols. Ifthe slot boundary is crossed, the terminal may divide repetition PUSCHtransmission of L*K symbols on the basis of the slot boundary. Referringto FIG. 24 , when it is given that an index of the start symbol of PUSCHis 4, a length is 4, and the number of repetition transmissions is 5,since 20 symbols from a symbol corresponding to index 4 cross a slotboundary, the terminal may divide the 20 symbols on the basis of theslot boundary. Therefore, in FIG. 24 , two repetition PUSCHtransmissions may be performed.

iii) Referring to FIG. 25 , a base station transmits time domainresource assignment information (S: start symbol index, L: length) forfirst repetition PUSCH transmission of PUSCH to a terminal. Then, thenumber (K) of repetitions is transmitted. The terminal determinessymbols in which repetition PUSCH transmission is to be performed, viathe received information. Subsequent repetition PUSCH transmission iscontinuously performed in a symbol immediately subsequent to a symbol inwhich first repetition PUSCH transmission is performed. In this case, ifone repetition PUSCH transmission crosses a slot boundary, the terminaldoes not perform the repetition PUSCH transmission. If one repetitionPUSCH transmission overlaps an SS/PBCH block or a symbol configured forDL in a semi-static UL/DL configuration, the terminal may not performthe repetition PUSCH transmission. For example, in FIG. 25 , thirdrepetition PUSCH transmission should be performed in symbols 12 and 13of a first slot and in symbols 0 and 1 of a second slot, but thiscrosses a slot boundary and no transmission is thus performed.

iv) Referring to FIG. 26 , a base station transmits time domain resourceassignment information (S: start symbol index, L: length) for firstrepetition PUSCH transmission of PUSCH to a terminal. Then, the number(K) of repetitions is transmitted. The terminal determines symbols inwhich repetition PUSCH transmission is to be performed, via the receivedinformation. Subsequent repetition PUSCH transmission is continuouslyperformed in a symbol immediately subsequent to a symbol in which firstrepetition PUSCH transmission is performed. If symbols assigned to onerepetition PUSCH transmission cross a slot boundary, the terminal maydivide, based on the slot boundary, the symbols assigned for therepetition PUSCH transmission, and the divided symbols may be includedin adjacent repetition PUSCH transmission in the same slot. If there isno adjacent repetition PUSCH transmission in the same slot, the terminalmay perform repetition PUSCH transmission by using the symbols. Forexample, symbols (symbols 12 and 13 of a first slot and symbols 0 and 1of a second slot) assigned to third repetition PUSCH transmission ofFIG. 26 cross the slot boundary. Accordingly, division may be performedin units of two symbols (symbols 12 and 13, and symbols 0 and 1)according to the slot boundary, first two symbols may be included inpreceding repetition PUSCH transmission, and second two symbols may beincluded in subsequent repetition PUSCH transmission.

FIG. 27 is a diagram illustrating repetition PUSCH transmissionaccording to an embodiment of the present disclosure.

Referring to FIG. 27 , a base station may additionally transmit, to aterminal, information on symbol(s) unavailable for repetition PUSCHtransmission. The terminal may perform repetition PUSCH transmissionusing the aforementioned i) to iv) transmission methods, wherein, ifsymbols unavailable for the repetition PUSCH transmission overlap asymbol to which the repetition PUSCH transmission is allocated, thesymbols unavailable for repetition PUSCH transmission may be excludedfrom the repetition PUSCH transmission. If the symbols unavailable forrepetition PUSCH transmission overlap the symbol to which the repetitionPUSCH transmission is allocated, the terminal may not perform therepetition PUSCH transmission. Information on the symbol(s) unavailablefor repetition PUSCH transmission may be configured to the terminal viaan RRC signal. The symbol(s) unavailable for repetition PUSCHtransmission may be configured to the terminal via the RRC signal, andwhich symbol(s) among the configured symbol(s) unavailable forrepetition PUSCH transmission cannot be actually used for repetitionPUSCH transmission may be indicated. When the base station configures,to the terminal, the symbol(s) unavailable for repetition PUSCHtransmission, via a time domain resource assignment (TDRA) table,configuration may be performed differently for each entry in each table.The terminal may be configured/indicated with one entry of the TDRAtable configured via DCI, and may perform repetition PUSCH transmissionaccording to the symbol(s) unavailable for repetition PUSCHtransmission, which are configured in the entry.

Hereinafter, in the present specification, a method of obtaining a sizeof a transport block (TB) when performing repetition PUSCH transmissionwill be described. According to the 3GPP standard documents, a size of aTB may be proportional to the number of REs of a resource to which PUSCHis allocated. That is, PUSCH to which more REs are assigned may have alarger TB size. However, as described above, the number of REs availablefor each repetition PUSCH transmission may be different. For example,first repetition PUSCH transmission may use 2 symbols and secondrepetition USCH transmission may use 10 symbols. In this case, it isnecessary to determine the number of which REs is to be used todetermine a size of a TB.

First, a method is to determine a size of a TB so as to enable decodingof first PUSCH (decodable). A reason for using repetition PUSCHtransmission is to reduce a delay time by fast decoding success.Therefore, it is important that first PUSCH is transmitted decodably.Accordingly, the terminal may determine the size of the TB according tothe number of REs for first PUSCH. The terminal may determine the sizeof the TB, based on a minimum value of REs corresponding to repetitionPUSCH transmission having a redundancy version (RV) value of 0. However,when the size of the TB is determined based on the number of REs forfirst PUSCH, since the number of REs occupied by another PUSCH is notconsidered, there is a problem that an optimal TB size cannot bedetermined. For example, when the number of REs used for first PUSCHtransmission is more than the number of REs used for second PUSCHtransmission, if the size of the TB is determined based on the number ofREs used for first PUSCH transmission, since the number of REs used forsecond PUSCH transmission is less, a code rate may be increased, whichmay cause performance degradation.

Therefore, if the number of REs used for first repetition PUSCHtransmission is less than an average (that is, a value obtained bydividing the number of REs used for all repetition PUSCH transmissionsby the number of repetitions) of the number of REs used for allrepetition transmissions,

-   the size of the TB is determined according to the number of REs used    for first repetition PUSCH transmission, and otherwise, the size of    the TB is determined according to the average value of the number of    REs used for all repetition transmissions. That is, if the size of    the TB determined according to the number of REs used for first    repetition PUSCH transmission is smaller than an average TB size    (that is, a value obtained by dividing the sum of the sizes of TBs    determined according to the number of REs used for respective    repetition PUSCH transmissions by the number of repetition    transmissions) determined according to the number of REs used for    all repetition transmissions, the size of the TB is determined    according to the number of REs used for first repetition PUSCH    transmission, and otherwise, the size of the TB is determined by the    average TB size according to the number of REs used for all    repetition transmissions.

Hereinafter, in the present specification, a method of interpretingscheduling information of PDSCH or PUSCH will be described.

The base station may configure a set (or table) of assignmentinformation of possible PUSCH time domains via an RRC signal in order toindicate assignment information of the time and frequency domains ofPUSCH to the terminal, and may indicate one piece of time domainassignment information in the configured set (or table) by DCI forscheduling of PUSCH. In order to configure a set (or table) ofassignment information of the time domain of PUSCH, the base station mayindicate, via the RRC signal, a relative PUSCH start symbol index(S_(start)′) and a length of PUSCH (L_(symbols)) to the terminal throughSLIV using Equation 7 as follows.

[Equation 7] if L_(symbols)−1≤floor (N_(symbols)/2) then SLIV =N_(symbols) (L_(symbols)−1) +S_(start) ′ else SLIV = N_(symbols)(N_(symbols)−L_(symbols)+1) + (N_(symbols)−1−S_(start) ′ ) WhereL_(symbols) >= 1 and shall not exceed N_(symbols)−S_(start) ′ .

In this case, N_(symbols) is the number of symbols included in a slotand is 14.

The terminal may obtain, from S_(start)=S_(start)′+R, an index(S_(start)) of a start symbol to which PUSCH is actually assigned, onthe basis of the relative PUSCH start symbol index (S_(start)′) obtainedvia an SLIV value calculated using Equation 7. Here, R is a referencesymbol index value of the PUSCH start symbol index (S_(start)′). AnS_(start) value is an index of a symbol in which PUSCH transmissionstarts in a slot, and may have one value in the range of {0, 1, . . . ,N_(symbols)−1} if N_(symbols) OFDM symbols are included in one slot.

Hereinafter, in the present specification, a method of determining an Rvalue will be described.

The terminal may always assume that R=0. That is, an index of areference symbol may always be fixed to a first symbol of a slot. Thisis a method in which a first symbol is a symbol corresponding to asymbol index indicated by an SLIV, in a symbol duration in which PUSCHis actually transmitted.

SLIV may be calculated using Equation 8.

[Equation 8] ● If L+S≤ 14, then ● if (L −1) ≤ 7 ▪ SLIV =14*(L−1) +S,● else ▪ SLIV = 14* (14−L+1) + (14−1−S) ● If L+S>14, then ● if (L −1) ≤6 ▪ SLIV= 14* (14−L+1) + (14−1−S) ● else ▪ SLIV=14* (L−1) +S

S indicates a start symbol of PUSCH in a slot and has one value among 0,1, 2, . . . , 13, and L is the number of symbols occupied by PUSCH. IfPUSCH is configured to be repeatedly transmitted, L is a length of firstrepetition transmission of PUSCH. If L+S is less than or equal to 14 (inthis case, PUSCH is located in one slot), L+S has the same value as SLIVin Rel-15, and if L+S is greater than 14 (in this case, PUSCH is locatedacross two slots), a value other than the SLIV in Rel-15 is used.Therefore, SLIV values for all combinations of S=0, 1, . . . , 13 andL=1, 2, . . . , 14 may be defined. The terminal may determine an S valueand an L value from an SLIV value. SLIV values for Equation 8 are shownin Table 5 below. In Table 5 below, the horizontal axis is S=0, 1, . . ., 13, and the vertical axis is L=1, 2, . . . , 14. Values in the tableare SLIV values.

TABLE 5 S = 0 1 2 3 4 5 6 7 8 9 10 11 12 13 L = 1 0 1 2 3 4 5 6 7 8 9 1011 12 13 2 14 15 16 17 18 19 20 21 22 23 24 25 26 182 3 28 29 30 31 3233 34 35 36 37 38 39 169 168 4 42 43 44 45 46 47 48 49 50 51 52 156 155154 5 56 57 58 59 60 61 62 63 64 65 143 142 141 140 6 70 71 72 73 74 7576 77 78 130 129 128 127 126 7 84 85 86 87 88 89 90 91 117 116 115 114113 112 8 98 99 100 101 102 103 104 105 106 107 108 109 110 111 9 97 9695 94 93 92 118 119 120 121 122 123 124 125 10 83 82 81 80 79 131 132133 134 135 136 137 138 139 11 69 68 67 66 144 145 146 147 148 149 150151 152 153 12 55 54 53 157 158 159 160 161 162 163 164 165 166 167 1341 40 170 171 172 173 174 175 176 177 178 179 180 181 14 27 183 184 185186 187 188 189 190 191 192 193 194 195

The terminal may determine an R value according to a semi-static DL/ULconfiguration. The semi-static DL/UL configuration indicates that a basestation informs a terminal whether each symbol of a slot is for downlinktransmission (DL symbol) or for uplink transmission (UL symbol), via acell-specific RRC signal and a UE-specific RRC signal. A symbol that isnot indicated as a DL symbol and a UL symbol is a flexible symbol. A gapfor DL/UL switching of the terminal may be located in a flexible symbol.When a flexible symbol index starting immediately subsequent to DLsymbols of a slot, to which PUSCH is allocated, is denoted as X, theterminal may assume that a reference symbol index (R) of PUSCH is X.That is, the terminal may assume that the flexible symbol immediatelysubsequent to the DL symbol in the slot is the reference symbol index.When the flexible symbol index starting immediately subsequent to DLsymbols of the slot, to which PUSCH is allocated, is denoted as X, theterminal may assume that the reference symbol index (R) of PUSCH is X+Y.Y may be a value indicating the number of symbols for a gap for DLtransmission and UL transmission. The number Y of symbols for a gap maybe obtained via a timing advance (TA) value and an OFDM symbol length,or may be set/configured for the terminal by the base station. A Y valuemay be 1 or 2.

The terminal may determine an R value according to CORESET in whichPDCCH is received. Specifically, the terminal may obtain an R value fromindices of OFDM symbol(s) in which CORESET having received DCI forscheduling of PUSCH, which is transmitted from the base station, islocated. Since CORESET is a downlink signal, PUSCH cannot be scheduledfor a symbol corresponding to CORESET. Also, PUSCH transmissionscheduling cannot be performed before CORESET. Accordingly, a symbol inwhich the terminal can be scheduled with PUSCH transmission earliest isa symbol immediately subsequent to CORESET. Therefore, an index of asymbol immediately subsequent to CORESET may be used as a referencesymbol index for determining a start symbol of PUSCH. For example, if anindex of an OFDM symbol, in which CORESET having received DCI forscheduling of PUSCH transmission starts, is K and a length of CORESET isD, the terminal may obtain a reference symbol index R via K+D. Asanother example, a gap for Rx-to-Tx switching is required for theterminal to transmit PUSCH immediately after receiving CORESET.Accordingly, the reference symbol index may be determined inconsideration of the gap. For example, if an index of an OFDM symbol, inwhich CORESET having received DCI for scheduling of PUSCH transmissionstarts, is K and a length of CORESET is D, the terminal may obtain areference symbol index R via K+D+Y. Y is the number of gap symbols, andmay be 1 or 2. When the base station configures/indicates the terminalto transmit PUSCH by using a slot in which PDCCH for scheduling of PUSCHis received, the terminal may determine a reference symbol index bymeans of the aforementioned method. However, if the base stationconfigures/indicates the terminal to transmit PUSCH by using a slotother than the slot in which PDCCH for scheduling of PUSCH is received,the terminal may assume that R=0. That is, the terminal may determinewhether the slot to which PUSCH is assigned and the slot to which PDCCHis assigned are the same, and then may determine an R value. In orderfor the terminal to transmit PUSCH immediately after receiving CORESET,time for calculating PUSCH is required. A minimum time required tocalculate PUSCH after reception of PDCCH is referred to as a PUSCHpreparation time (T_(proc,2)). That is, the terminal does not expectPUSCH transmission to be configured/indicated by the base station beforethe PUSCH preparation time. By using this information, the terminal maydetermine a reference symbol index. For example, if an index of an OFDMsymbol, in which CORESET having received DCI for scheduling of PUSCHtransmission starts, is K and a length of CORESET is D, the terminal mayobtain a reference symbol index (R) via (K+D+T)mod N_(symbols). Here, Tis a value indicating the PUSCH preparation time by using the number ofsymbols. A reason for performing mod N_(symbols) is to allow a referencesymbol index to have one of values among 0, 1, . . . , 13 because thereference symbol index should be located in a slot. If the terminal isscheduled with PUSCH in a slot including a symbol after T symbols from asymbol immediately subsequent to CORESET, the reference symbol index (R)may be assumed to be (K+D+T) mod N_(symbols), and if a slot subsequentto the slot is indicated, the reference symbol index R may be assumed tobe 0.

If subcarrier spacings (SCS) of a cell in which PDCCH is scheduled and acell in which PUSCH is scheduled are different, an index K of the symbolin which the CORESET starts and a length L value of the CORESET may beambiguous. For example, if an SCS (hereinafter, SCS1) of a first cell inwhich PDCCH is scheduled is greater than an SCS (hereinafter, SCS2) of asecond cell in which PUCCH is scheduled, one symbol of the first celland multiple symbols of the second cell overlap. In this case, a symbolcorresponding to the index (K) of the symbol in which CORESET starts maybe an earliest symbol among the symbols of the second cell, whichoverlaps the symbol in which CORESET of the first cell starts. A lengthof the symbol of the second cell, which overlaps CORESET of the firstcell may be obtained by multiplying a length of CORESET of the firstcell by SCS2/SCS1. Specifically, if the length of one symbol in thefirst cell is T, the length of one symbol in the second cell isT*SCS2/SCS1. Accordingly, when assuming that a symbol duration includingCORESET in the first cell is 2 symbols, a symbol duration in which PUCCHin the second cell is scheduled is 2*SCS2/SCS1. For example, when SCS2is 15 KHz and SCS1 is 30 KHz, CORESET of the first cell, which has alength of 2 symbols, overlaps 1 symbol (2*15 KHz/30 KHz) of the secondcell.

Hereinafter, in the present specification, a position of a DM-RS whenPUSCH is repeatedly transmitted will be described. A time domainresource assignment (TDRA) field of DCI for scheduling of PUSCH mayindicate not only a length of PUSCH but also a DM-RS location of PUSCH.If the terminal is indicated with PUSCH mapping type A, a DM-RS of PUSCHmay be transmitted at a fixed position within a slot. If the terminal isindicated with PUSCH mapping type B, the DM-RS of PUSCH may betransmitted in a first symbol among symbols to which PUSCH is allocated.That is, if the terminal is indicated with PUSCH mapping type B, theDM-RS may be transmitted in another symbol within the slot according toPUSCH scheduling.

If the base station configures/indicates the terminal to repeatedlytransmit PUSCH, and the terminal is indicated with PUSCH mapping type A,the DM-RS should be transmitted at a fixed position (symbol) of the slotaccording to PUSCH mapping type A. However, in a case of mini-slot-levelrepetition PUSCH transmission,

-   a symbol duration used for first repetition PUSCH transmission    includes a symbol in which a DM-RS is located (mapped) so that    transmission of the DM-RS is possible, but a symbol duration used    for second repetition PUSCH transmission may not include a symbol to    which the DM-RS is mapped. Therefore, when the terminal performs    repetition PUSCH transmission, it is necessary to determine where    the DM-RS is mapped to so as to be transmitted. Hereinafter, in the    present specification, a DM-RS transmission method will be    described.

First, provided is a method in which, in first repetition PUSCHtransmission, a DM-RS is transmitted on a mapped symbol according toPUSCH mapping type A, and in second repetition PUSCH transmission andsubsequent repetition PUSCH transmission thereof, a DM-RS is mapped to asymbol according to PUSCH mapping type B so as to be transmitted. Inother words, in the second repetition PUSCH transmission and subsequentrepetition PUSCH transmission thereof, the DM-RS may be transmitted on afirst symbol in which each repetition PUSCH transmission is performed.

Next, provided is a method in which, even though the terminal isindicated with PUSCH mapping type A via DCI, the terminal transmits aDM-RS in consideration of PUSCH mapping type B. The difference from theabove-described method is that the terminal follows PUSCH mapping type Beven in first repetition PUSCH transmission, instead of following PUSCHmapping type A.

FIG. 28 is a diagram for a method of locating a DM-RS in repetitionPUSCH transmission according to an embodiment of the present disclosure.

Next, provided is a method in which, if repetition PUSCH transmissionincludes a DM-RS symbol according to PUSCH mapping type A, a DM-RS istransmitted according to mapping time A and, otherwise, a DM-RS symbolis transmitted according to PUSCH mapping type B. Referring to FIG.28(a), a slot includes 6 symbols, and when a third symbol of each slotcorresponds to a position to which a DM-RS according to PUSCH mappingtype A is mapped, since a symbol duration in which first repetitionPUSCH transmission (first slot symbol 0 to symbol 2) and thirdrepetition PUSCH transmission (second slot symbol 0 to symbol 2) areperformed includes a DM-RS position (third symbol in slot, i.e., symbol2 in each slot) according to mapping type A, a terminal transmits aDM-RS in the symbol. The remaining symbol durations in which second andfourth repetition PUSCH transmissions are performed do not include theDM-RS position, and the terminal may thus transmit a DM-RS in a firstsymbol in the symbol durations in which repetition PUSCH transmission isperformed.

Subsequently, first repetition PUSCH transmission transmits a DM-RS in aDM-RS symbol according to PUSCH mapping type A, and second repetitionPUSCH transmission and subsequent repetition PUSCH transmission transmita DM-RS at the same position as that of the first repetition PUSCHtransmission in PUSCH. Referring to FIG. 28(b), a DM-RS by PUSCH mappingtype A is located in a third symbol in a symbol duration in which firstrepetition PUSCH transmission is performed. Accordingly, a DM-RSaccording to PUSCH mapping type A is also located in a third symbol of asymbol duration, in which repetition PUSCH transmission is performed, insubsequent repetition PUSCH transmission in the same manner. This is tolocate DM-RSs at equal intervals in the time domain in order to minimizea channel estimation error in a time varying channel.

Hereinafter, in the present specification, a position of a DM-RS ofPUSCH according to a reference symbol index will be described. A TDRAfield of DCI for scheduling of PUSCH may indicate not only a length ofPUSCH but also a DM-RS position of PUSCH. However, if a reference symbolindex (R) is not fixed to 0, there may be a case in which symbols inwhich PUSCH is scheduled do not include a symbol in which a DM-RSaccording to PUSCH mapping type A is located. In the current 3GPPstandards, since R is always fixed to 0, PUSCH symbols indicated by theTDRA field indicating SLIV and PUSCH mapping type A always include asymbol in which a DM-RS according to PUSCH mapping type A is located.Hereinafter, in the present specification, a method of determining aposition to which a DM-RS is mapped in PUSCH will be described.

i) If a symbol to which a DM-RS according to PUSCH mapping type A ismapped is included in PUSCH indicated using a reference symbol index,the DM-RS is transmitted in the symbol, and otherwise, the DM-RS may betransmitted according to PUSCH mapping type B. That is, if PUSCHdetermined according to the reference symbol index does not include asymbol in which a DM-RS according to PUSCH mapping type A is located,the DM-RS may be transmitted in a first symbol of PUSCH.

ii) If a terminal is indicated with PUSCH mapping type A by a basestation, the terminal may always assume that R=0 (that is, a symbolcorresponding to the reference symbol index is a first symbol of theslot), and when the terminal is indicated with PUSCH mapping type B bythe base station, R may be determined according to the aforementionedmethod. As such, by interpreting the reference symbol index differentlyaccording to a PUSCH mapping type, even if the terminal is indicatedwith PUSCH mapping type A by the base station, a case of not including asymbol to which a DM-RS is mapped does not occur.

Hereinafter, in the present specification, a method of determining areference symbol index of PDSCH will be described. As described above,similar to the method of determining a reference symbol index of PUSCH,a method of determining a reference symbol index (R) is also required ina case of downlink PDSCH.

The terminal may determine a reference symbol index of PDSCH, based onCORESET. Specifically, a first symbol of CORESET in which PDCCH forscheduling of PDSCH is received may be a reference symbol index ofPDSCH. For example, if a first symbol of CORESET in which PDCCH isreceived is an R-th symbol of a slot, and an SLIV of a TDRA field of thePDCCH indicates S and L, PDSCH may start at an R+S-th symbol of the slotand may have a length of L.

Hereinafter, in the present specification, a method of determining areference symbol index of PDSCH when cross-carrier scheduling isindicated will be described. If an SCS of a cell in which PDCCH isreceived and an SCS of a cell in which PDSCH is received are the same, afirst symbol of CORESET in which PDCCH is received may be determined asa reference symbol of PDSCH. However, if the SCS of the cell in whichPDCCH is received and the SCS of the cell in which PDSCH is received aredifferent, the method described below may be considered.

FIG. 29 is a diagram illustrating a method of determining a referencesymbol index of PDSCH according to an embodiment of the presentdisclosure.

i) If an SCS of a cell in which PDCCH is received and an SCS of a cellin which PDSCH is received are different, an index of an earliest symbolamong symbols of a cell in which PDSCH overlapping a first symbol ofCORESET of the PDCCH is transmitted may be determined as a referencesymbol index of PDSCH. FIG. 29(a) shows a case in which the SCS of thecell (DL cell #0) in which PDCCH is received is smaller than that of thecell (DL cell #1) in which PDSCH is received. The first symbol ofCORESET of PDCCH and two symbols (A and B) of the cell in which PDSCH isreceived may overlap. An index of a preceding symbol A among the twosymbols may be determined as a reference symbol index of PDSCH. If thefirst symbol of CORESET is symbol n of a slot of the cell in which PDCCHis received, the reference symbol index in the cell in which PDSCH isreceived is floor(n*^(2u1−u0))mod N_(symbol). Here, the SCS of the cellin which PDCCH is received is 2^(u1) 1 kHz, the SCS of the cell in whichPDSCH is received is 2^(u2) kHz, and N_(symbol) is the number of symbolsincluded in one slot.

ii) If an SCS of a cell in which PDCCH is received and an SCS of a cellin which PDSCH is transmitted are different, a latest symbol amongsymbols of the cell, in which PDSCH is transmitted, which overlap afirst symbol of CORESET of the PDCCH may be determined as a referencesymbol index of PDSCH. FIG. 29(a) shows a case in which the SCS of thecell (DL cell #0) in which PDCCH is received is smaller than that of acell (DL cell #1) in which PDSCH is received. The first symbol ofCORESET of PDCCH and two symbols (A and B) of the cell in which PDSCH isreceived may overlap. In this case, an index of a last symbol (B) of thetwo symbols may be determined as a reference symbol index of PDSCH. Ifthe first symbol of CORESET is symbol n of a slot of the cell in whichPDCCH is received, the reference symbol index in the cell in which PDSCHis received is ceil((n+1)*2^(u1−u0))−1 mod N_(symbol). Here, the SCS ofthe cell in which PDCCH is received is 2^(u1) kHz, the SCS of the cellin which PDSCH is received is 2^(u2) kHz, and N_(symbol) is the numberof symbols included in one slot.

iii) The aforementioned methods i) and ii) have a problem that an indexof a symbol starting before CORESET of PDCCH may be a reference symbolindex of PDSCH. If an index of a symbol starting before CORESET of PDCCHis a reference symbol index of PDSCH, a terminal needs to buffer thepreceding symbol. For example, FIG. 29(b) shows a case in which the SCSof the cell (DL cell #0) in which PDCCH is received is greater than thatof the cell (DL cell #1) in which PDSCH is received. In this case, thefirst symbol of CORESET overlaps one symbol A of the cell in which PDSCHis received. When the aforementioned methods i) and ii) are applied, anindex of symbol A is determined as a reference symbol index. However,symbol A starts before the first symbol of CORESET, and thus theterminal needs to perform buffering, which causes a problem ofincreasing complexity.

Accordingly, in order to solve this problem, an index of an earliestsymbol among symbols of the cell in which PDSCH is received, which donot precede the first symbol of CORESET of PDCCH, may be determined as areference symbol index. In FIG. 29(b), symbol A starts before the firstsymbol of CORESET, so that the index of symbol A cannot be a referencesymbol index. Therefore, an index of subsequent symbol B may bedetermined as a reference symbol index. Referring to FIG. 29(a), the SCSof the cell (DL cell #0) in which PDCCH is received is smaller than thatof the cell (DL cell #1) in which PDSCH is received, wherein symbol Aand the first symbol of CORESET start at the same time. Therefore, theindex of symbol A may be determined as a reference symbol index.

A method of determining a reference symbol index by a terminal on thebasis of CORESET may not be applied to cross-carrier scheduling. Thatis, the terminal does not expect an RRC configuration in which a methodof determining a reference symbol index on the basis of CORESET andcross-carrier scheduling are simultaneously applied. In other words, theterminal may treat this as an error case.

When the terminal is indicated with cross-carrier scheduling, theterminal may determine a first symbol index of a slot to be a referencesymbol index, and in a case of self-carrier scheduling (i.e., if PDCCHand PDSCH are transmitted in the same cell), the terminal may determinea reference symbol index according to methods i) to iii) describedabove. The terminal is indicated with cross-carrier scheduling, and ifthe SCS of the cell in which PDCCH is received and the SCS of the cellin which PDSCH is received are different, a first symbol index of theslot may be determined as a reference symbol index, and in a case ofself-carrier scheduling or if the SCS of the cell in which PDCCH isreceived and the SCS of the cell in which PDSCH is received are thesame, a reference symbol index may be determined according to methods i)to iii) described above.

The method of determining a reference symbol index of PDSCH may beapplied when PDCCH and PDSCH are received in the same slot. In otherwords, the method may be applied when the number (K0) between a slot inwhich PDCCH is received and a slot in which reception of the PDSCH isscheduled is 0. That is, if K0 is 0, PDCCH and PDSCH may be located inthe same slot. The method of determining a reference symbol index of thePDSCH may be applied when PDSCH mapping type B is indicated (when avalue of K0 is 0). The method of determining a reference symbol index ofPDSCH may be applied when PDCCH and PDSCH are received in the same slot(when a value of K0 is 0) and PDSCH mapping type B is indicated (when avalue of K0 is 0). If the aforementioned method is not applied, theterminal may determine an index of a first symbol of the slot, as areference symbol index of PDSCH.

Hereinafter, in the present specification, a method of determining aposition of a DM-RS of PDSCH according to a reference symbol index willbe described. A TDRA field of DCI for scheduling of PDSCH may indicatenot only a length of PDSCH but also a DM-RS position of PDSCH. However,if a reference symbol index (R) of PDSCH is not fixed to 0, symbols inwhich PDSCH is scheduled may not include a symbol in which a DM-RSaccording to PDSCH mapping type A is mapped. In the current 3GPPstandards, since R is always fixed to 0, PDSCH symbols indicated by aTDRA field indicating SLIV and PDSCH mapping type A always include asymbol in which a DM-RS according to PDSCH mapping type A is mapped. Inthe present disclosure, it is necessary to determine a position at whicha DM-RS should be transmitted in the PDSCH.

If PDSCH configured/indicated based on a reference symbol index includesa symbol in which a DM-RS according to PDSCH mapping type A should betransmitted, the DM-RS is transmitted on the symbol, and otherwise theDM-RS may be transmitted according to PDSCH mapping type B. That is, ifPDSCH configured/indicated based on a reference symbol index does notinclude a symbol in which a DM-RS according to PDSCH mapping type Ashould be transmitted, the DM-RS may be transmitted in a first symbol ofPDSCH.

As another embodiment of the present disclosure, if the terminal isindicated with PDSCH mapping type A, the terminal always considers thatR=0 (i.e., it is assumed that a reference index is a first symbol of aslot), and in a case of PDSCH mapping type B, R may be determinedaccording to the aforementioned embodiment. As such, by interpreting areference index differently according to a PDSCH mapping type, in a caseof PDSCH mapping type A, a case where a DM-RS symbol is not includeddoes not occur.

FIG. 30 is a flowchart illustrating an operation procedure in a terminalperforming a method of transmitting a shared channel according to anembodiment of the present disclosure.

That is, illustrated is a procedure of performing the methods(embodiments) described with reference to FIG. 12 to FIG. 29 by aterminal.

First, a terminal receives, from a base station, first resourceinformation for transmission or reception of a shared channel, in S3001.

The first resource information may include a relative start symbol indexand a symbol length in a time domain resource for transmission orreception of the shared channel.

The terminal receives the shared channel from the base station on afirst resource determined based on the first resource information ortransmits the shared channel to the base station on the first resource,in S3002.

A start symbol index of the first resource may be determined based onthe relative start symbol index and a predefined reference symbol index.

The reference symbol index may be 0 or may be determined based on alength and a start symbol of a resource including the first resourceinformation.

The first resource may be determined based on a first subcarrier spacing(SCS) of a first cell including the first resource information and asecond SCS of a second cell including the shared channel.

If the first SCS and the second SCS are the same, the reference symbolindex may be an index of a first symbol among symbols including thefirst resource information of the first cell.

If the first SCS is smaller than the second SCS, the reference symbolindex may be an index of an earliest symbol among symbols including theshared channel of the second cell, which overlap in the time domain withsymbols including the first resource information of the first cell.

If the first SCS is smaller than the second SCS, the reference symbolindex may be an index of a last symbol among symbols including theshared channel of the second cell, which overlap in the time domain withsymbols including the first resource information of the first cell.

If the first SCS is greater than the second SCS, the reference symbolindex may be an index of an earliest symbol among symbols that do notprecede symbols including the first resource information, from amongsymbols including the shared channel of the second cell, which overlapin the time domain with symbols of the first cell.

The first resource information may further include a first position of ademodulation-reference signal (DM-RS) mapped to the first resource.

If the first resource includes the first position, the DM-RS may bemapped to the first position, and if the first resource does not includethe first position, the DM-RS may be mapped to a symbol indicated by thestart symbol index of the first resource.

If the shared channel is transmitted first on the first resource andrepeatedly transmitted second on a second resource, the DM-RS may bemapped to the first position in the first resource, and the DM-RS may bemapped to a first symbol of the second resource in the second resource.

If the shared channel is transmitted first on the first resource andrepeatedly transmitted second on the second resource, the DM-RS may bemapped to the first position in the first resource. In the secondresource, the DM-RS is mapped to a position corresponding to the firstposition, and the corresponding position may be a position separatedfrom a first symbol of a second duration by a duration that the firstposition and a first symbol of the first resource are separated.

The DM-RS may be mapped to a symbol indicated by the start symbol indexof the first resource regardless of the first position.

The terminal may receive, from the base station, second resourceinformation for transmission or reception of the shared channel.

The second resource information may include information on a use ofmultiple symbols constituting a slot of the first resource.

The reference symbol index may be determined based on the first resourceinformation and the second resource information.

When the terminal transmits the shared channel to the base station onthe first resource, the reference symbol index is an index of a symbolwhich has a direction configured to flexible and is immediatelysubsequent to a last symbol the use of which is configured to downlinkfrom among the multiple symbols.

The use of symbols may have the same meaning as the aforementionedsymbol direction. Specifically, the use of symbols indicates whether asymbol is used for downlink transmission, is used for uplinktransmission, or is a flexible symbol that may be used for either one ofdownlink and uplink.

When the terminal transmits the shared channel to the base station onthe first resource, the reference symbol index may be an index of asymbol which has a use configured to flexible or uplink and isimmediately subsequent to a gap symbol located after a last symbol theuse of which is configured to downlink, from among the multiple symbols.

Although the method and system of the present disclosure have beendescribed in connection with specific embodiments, some or all of theircomponents or operations may be implemented using a computing systemhaving a general-purpose hardware architecture.

The above description of the present disclosure is for illustrativepurposes only, and those of ordinary skill in the art to which thepresent disclosure pertains will be able to understand that otherspecific forms can be easily modified without changing the technicalspirit or essential features of the present disclosure. Therefore, itshould be understood that the embodiments described above areillustrative and non-limiting in all respects. For example, eachcomponent described as a single type may be implemented in a distributedmanner, and similarly, components described as being distributed mayalso be implemented in a combined form.

The scope of the present disclosure is indicated by the claims to bedescribed later rather than the detailed description, and all changes ormodified forms derived from the meaning and scope of the claims andtheir equivalent concepts should be construed as being included in thescope of the present disclosure.

1-20. (canceled)
 21. A method for receiving a shared channel by aterminal in a wireless communication system, the method comprising:receiving, from a base station, first resource information on a controlchannel, wherein the first resource information includes informationrelated to a symbol length and a relative start symbol index; andreceiving, from the base station, a shared channel on a first resourcedetermined based on the first resource information, wherein a startsymbol index of the first resource is determined based on the relativestart symbol index and a reference symbol index, wherein the referencesymbol index is determined based on a resource allocated for amonitoring of the control channel, wherein the first resource isdetermined based on a first subcarrier spacing (SCS) for the controlchannel and a second SCS for the shared channel.
 22. The method of claim21, wherein the control channel is included in a first cell, wherein theshared channel is included in a second cell.
 23. The method of claim 21,wherein the reference symbol index is an index of an earliest symbolamong symbols for the monitoring of the control channel.
 24. The methodof claim 23, wherein, the first SCS and the second SCS are the same. 25.The method of claim 21, wherein the first resource information furtherincludes information related to a position of a demodulation-referencesignal (DM-RS).
 26. The method of claim 25, wherein one or more symbolsto which the DM-RS is mapped include an earliest symbol of the firstresource.
 27. A terminal for receiving a shared channel in a wirelesscommunication system, the terminal comprising: a transceiver; aprocessor; and a memory connected to the processor and configured tostore instructions for operations executed by the processor, wherein theoperations comprise: receiving, from a base station, first resourceinformation on a control channel, wherein the first resource informationincludes information related to a symbol length and a relative startsymbol index; and receiving, from the base station, a shared channel ona first resource determined based on the first resource information,wherein a start symbol index of the first resource is determined basedon the relative start symbol index and a reference symbol index, whereinthe reference symbol index is determined based on a resource allocatedfor a monitoring of the control channel, wherein the first resource isdetermined based on a first subcarrier spacing (SCS) for the controlchannel and a second SCS for the shared channel.
 28. The terminal ofclaim 27, wherein the control channel is included in a first cell,wherein the shared channel is included in a second cell.
 29. Theterminal of claim 27, wherein the reference symbol index is an index ofan earliest symbol among symbols for monitoring the control channel. 30.The terminal of claim 29, wherein, the first SCS and the second SCS arethe same.
 31. The terminal of claim 27, wherein the first resourceinformation further includes information related to a position of ademodulation-reference signal (DM-RS).
 32. The terminal of claim 31,wherein one or more symbols to which the DM-RS is mapped include anearliest symbol of the first resource.
 33. A method for transmitting ashared channel by a base station in a wireless communication system, themethod comprising: transmitting, to a terminal, first resourceinformation for reception of a shared channel on a control channel,wherein the first resource information includes information related to asymbol length and a relative start symbol index in a time domainresource for reception of the shared channel; and transmitting, to theterminal, the shared channel on a first resource determined based on thefirst resource information, wherein a start symbol index of the firstresource is determined based on the relative start symbol index and areference symbol index, wherein the reference symbol index is determinedbased on a resource allocated for a monitoring of the control channel,wherein the first resource is determined based on a first subcarrierspacing (SCS) for the control channel and a second SCS for the sharedchannel.
 34. The method of claim 33, wherein the control channel isincluded in a first cell, wherein the shared channel is included in asecond cell.
 35. The method of claim 33, wherein the reference symbolindex is an index of an earliest symbol among symbols for monitoring thecontrol channel.
 36. The method of claim 35, wherein, the first SCS andthe second SCS are the same.
 37. The method of claim 33, wherein thefirst resource information further includes information related to aposition of a demodulation-reference signal (DM-RS).
 38. The method ofclaim 37, wherein one or more symbols to which the DM-RS is mappedinclude an earliest symbol of the first resource.